Last Updated at Saturday, 24th March, 2007 (01:20)
Applied Physics Letters (APL)
Creep in protective alpha-Al[sub 2]O[sub 3] thermally grown on beta-NiAl
B. W. Veal, A. P. Paulikas, and P. Y. Hou
The authors report systematic measurements of creep relaxation in alpha-Al[sub 2]O[sub 3], thermally grown in air on (100) single crystals of stoichiometric beta-NiAl, at temperatures between 950 and 1100 degrees C. Creep was monitored using time dependent in situ measurements of strain relaxation ... [Appl. Phys. Lett. 90, 121914 (2007)] published Thu Mar 22, 2007.
Spontaneous charge transfer at organic-organic homointerfaces to establish thermodynamic equilibrium
S. Duhm, H. Glowatzki, J. P. Rabe, N. Koch, and R. L. Johnson
The energy level alignment of alpha,omega-dihexylsexithienyl (DH6T) mono- and multilayers on tetrafluorotetracyanoquinodimethane (F4-TCNQ) precovered Ag(111) and polycrystalline Au substrates was investigated with ultraviolet photoelectron spectroscopy. For certain F4-TCNQ precoverages molecular lev ... [Appl. Phys. Lett. 90, 122113 (2007)] published Thu Mar 22, 2007.
Defect distribution in a-plane GaN on Al[sub 2]O[sub 3]
F. Tuomisto, T. Paskova, R. Kroger, S. Figge, D. Hommel et al.
The authors studied the structural and point defect distributions of hydride vapor phase epitaxial GaN film grown in the [1120] a direction on (1102) r-plane sapphire with metal-organic vapor phase deposited a-GaN template using transmission electron microscopy, secondary ion mass spectrometry, and ... [Appl. Phys. Lett. 90, 121915 (2007)] published Thu Mar 22, 2007.
Acoustic Rayleigh scattering at individual micron-sized bubbles
V. Sboros, S. D. Pye, T. A. Anderson, C. M. Moran, and W. N. McDicken
A microacoustic system based on a wide-bandwidth commercial piezoelectric transducer is presented in this letter. The system allows objective measurement of nonlinear Rayleigh scatter from single microbubbles. Two different types of microbubbles were exposed to a range of ultrasonic frequencies and ... [Appl. Phys. Lett. 90, 123902 (2007)] published Thu Mar 22, 2007.
Enhanced photocatalytic activity of Ag microgrid connected TiO[sub 2] nanocrystalline films
Feng Pan, Junying Zhang, Weiwei Zhang, Tianmin Wang, and Chao Cai
One reason for the high degree of photogenerated carrier recombination was found to be the charge accumulation caused by the uneven reaction area on the photocatalyst surface. The authors connected TiO[sub 2] nanoparticles with conducting Ag microgrid. Obvious photocatalytic activity improvement (81 ... [Appl. Phys. Lett. 90, 122114 (2007)] published Thu Mar 22, 2007.
Unusual size dependence of the optical emission gap in small hydrogenated silicon nanoparticles
X. Wang, R. Q. Zhang, S. T. Lee, T. A. Niehaus, and Th. Frauenheim
It is well known that the electronic and optical absorption gaps of hydrogenated silicon nanoparticles are inversely proportional to the particle size. Here, the authors show that their optical emission gaps are remarkably different and dully dependent on the size for those smaller than 1.5 nm, bas ... [Appl. Phys. Lett. 90, 123116 (2007)] published Thu Mar 22, 2007.
Nanoscale polarization manipulation and imaging of ferroelectric Langmuir-Blodgett polymer films
Brian J. Rodriguez, Stephen Jesse, Sergei V. Kalinin, Jihee Kim, Stephen Ducharme et al.
Piezoresponse force microscopy has been used to manipulate and image polarization of ferroelectric polymer Langmuir-Blodgett films at the nanoscale, achieving polarization control with a resolution below 50 nm and imaging resolution below 5 nm. Individual regions showed square polarization-voltage ... [Appl. Phys. Lett. 90, 122904 (2007)] published Thu Mar 22, 2007.
Investigations of enhanced device characteristics in pentacene-based field effect transistors with sol-gel interfacial layer
T. Cahyadi, J. N. Tey, S. G. Mhaisalkar, F. Boey, V. R. Rao et al.
Pentacene films grown on sol-gel silica dielectrics showed a significant enhancement in field effect mobility, threshold voltages, and subthreshold swings. This letter investigates the contributing factors for the enhanced device characteristics. The smoother and more hydrophobic film surfaces of so ... [Appl. Phys. Lett. 90, 122112 (2007)] published Thu Mar 22, 2007.
Dynamics of mode competition in a gigawatt-class magnetically insulated line oscillator
D. H. Kim, H. C. Jung, S. H. Min, S. H. Shin, and G. S. Park
An axial mode competition is observed in a 1 GHz magnetically insulated line oscillator operating at gigawatt power level with a pulse duration of 130 ns. A fast-growing axial mode adjacent to desired pi-mode starts up first and hops to the slow-growing and stable pi mode. The dynamics of the mode ... [Appl. Phys. Lett. 90, 124103 (2007)] published Thu Mar 22, 2007.
Large magnetoresistance in Co/Ni/Co ferromagnetic single electron transistors
R. S. Liu, H. Pettersson, L. Michalak, C. M. Canali, D. Suyatin et al.
The authors report on magnetotransport investigations of nanoscaled ferromagnetic Co/Ni/Co single electron transistors. As a result of reduced size, the devices exhibit single electron transistor characteristics at 4.2 K. Magnetotransport measurements carried out at 1.8 K reveal tunneling magnetor ... [Appl. Phys. Lett. 90, 123111 (2007)] published Thu Mar 22, 2007.
Flexible conjugated polymer photovoltaic cells with controlled heterojunctions fabricated using nanoimprint lithography
Myung-Su Kim, Jin-Sung Kim, Jae Cheol Cho, Max Shtein, L. Jay Guo et al.
The authors describe conjugated polymer-based photovoltaic devices in which the shape and area of the interface between the electron donor and acceptor layers were controllably varied using nanoimprint lithography. The short circuit current is shown to increase with the interfacial area of the heter ... [Appl. Phys. Lett. 90, 123113 (2007)] published Thu Mar 22, 2007.
Tension-compression asymmetry in homogeneous dislocation nucleation in single crystal copper
M. A. Tschopp and D. L. McDowell
This letter addresses the dependence of homogeneous dislocation nucleation on the crystallographic orientation of pure copper under uniaxial tension and compression. Molecular dynamics simulation results with an embedded-atom method potential show that the stress required for homogeneous dislocation ... [Appl. Phys. Lett. 90, 121916 (2007)] published Thu Mar 22, 2007.
Photoluminescence characterization of Zn[sub 1 - x]Mg[sub x]O epitaxial thin films grown on ZnO by radical source molecular beam epitaxy
H. Shibata, H. Tampo, K. Matsubara, A. Yamada, K. Sakurai et al.
The authors report that high-quality Zn[sub 1x]Mg[sub x]O alloys are very brilliant light emitters, even more brilliant than ZnO, particularly in the high-temperature region; both the emission bandwidth and the oscillator strength of the photoluminescence from Zn[sub 1x]Mg[sub x]O alloys increase re ... [Appl. Phys. Lett. 90, 124104 (2007)] published Thu Mar 22, 2007.
Subnitride and valence band offset at Si[sub 3]N[sub 4]/Si interface formed using nitrogen-hydrogen radicals
Masaaki Higuchi, Shigetoshi Sugawa, Eiji Ikenaga, Jiro Ushio, Hiroshi Nohira et al.
The authors measured soft x-ray-excited angle-resolved photoemission from Si 2p, N 1s, and O 1s core levels, and valence band for nitride films formed on Si(100), Si(111), and Si(110) using nitrogen-hydrogen radicals with the same probing depth. The Si[sub 3]N[sub 4]/Si interfaces formed exhibited a ... [Appl. Phys. Lett. 90, 123114 (2007)] published Thu Mar 22, 2007.
Reduced threshold current in (111)B grown InGaAs/AlGaAs laser diodes: The positive role of piezoelectric effect
G. Deligeorgis, G. Dialynas, Z. Hatzopoulos, and N. T. Pelekanos
The authors demonstrate that (111)B grown InGaAs/AlGaAs laser diodes outperform their (100) counterparts, in terms of lower threshold currents observed for all temperature and cavity lengths tested. A low temperature threshold current density as low as 15 A/cm[sup 2] has been observed in (111)B gro ... [Appl. Phys. Lett. 90, 121126 (2007)] published Thu Mar 22, 2007.
Ordering of ErAs nanoparticles embedded in epitaxial InGaAs layers
Dmitri O. Klenov, Joshua M. O. Zide, James M. LeBeau, Arthur C. Gossard, and Susanne Stemmer
The authors report on the microstructures of semimetallic ErAs nanoparticles embedded in epitaxial InGaAs layers by codeposition of Er. The size of the particles (13 nm) was approximately independent of the amount of deposited Er. At large ErAs concentrations (>3 at. %), the particles showed a st ... [Appl. Phys. Lett. 90, 121917 (2007)] published Thu Mar 22, 2007.
Coherent detection of terahertz pulses based on two-photon absorption in a photodiode
Arno Schneider and Peter Gunter
The authors present a simple and robust method for the measurement of the terahertz-induced lensing effect that may be used for the coherent detection of few-cycle terahertz pulses. It is based on two-photon absorption of a 1.5 [mu]m probe pulse in a standard silicon photodiode. The change in the s ... [Appl. Phys. Lett. 90, 121125 (2007)] published Thu Mar 22, 2007.
Transmission line impedance of carbon nanotube thin films for chemical sensing
G. Esen, M. S. Fuhrer, M. Ishigami, and E. D. Williams
The authors measure the resistance and frequency-dependent gate capacitance of carbon nanotube (CNT) thin films in ambient, vacuum, and under low pressure (10[sup 6] Torr) analyte environments. They model the CNT film as a RC transmission line and show that changes in the measured capacitance as a ... [Appl. Phys. Lett. 90, 123510 (2007)] published Thu Mar 22, 2007.
Electrical characteristics and interface structure of HfAlO/SiON/Si(001) stacks
V. Edon, Z. Li, M.-C. Hugon, B. Agius, C. Krug et al.
The electrical characteristics of RuO[sub 2]/HfAlO/SiON/Si(001) capacitors prepared by thermal nitridation of the Si substrate previously to HfAlO ultrathin film deposition were determined. A dielectric constant of 19 and a gate current density of 67 mA/cm[sup 2] for an equivalent oxide thickness o ... [Appl. Phys. Lett. 90, 122905 (2007)] published Thu Mar 22, 2007.
Mechanism of molecular beam epitaxy growth of GaN nanowires on Si(111)
R. K. Debnath, R. Meijers, T. Richter, T. Stoica, R. Calarco et al.
GaN nanowires have been grown without external catalyst on Si(111) substrates by plasma-assisted molecular beam epitaxy. Nanowire aspect ratios (length/diameter) of about 250 have been achieved. During the initial stage of the growth, there is a nucleation process in which the number of wires increa ... [Appl. Phys. Lett. 90, 123117 (2007)] published Thu Mar 22, 2007.
Improved conductivity of transparent single-wall carbon nanotube thin films via stable postdeposition functionalization
Bhavin B. Parekh, Giovanni Fanchini, Goki Eda, and Manish Chhowalla
A simple postdeposition method for improving the conductivity of transparent and conducting single-wall carbon nanotube (SWNT) thin films via exposure to nitric acid and thionyl chloride is reported. A systematic study on a range of films of variable density and from different commercial sources of ... [Appl. Phys. Lett. 90, 121913 (2007)] published Thu Mar 22, 2007.
Precise replication of antireflective nanostructures from biotemplates
Hongjun Gao, Zhongfan Liu, Jin Zhang, Guoming Zhang, and Guoyong Xie
The authors report herein a new type of nanonipple structures on the cicada's eye and the direct structural replication of the complex micro- and nanostructures for potential functional emulation. A two-step direct molding process is developed to replicate these natural micro- and nanostructures usi ... [Appl. Phys. Lett. 90, 123115 (2007)] published Thu Mar 22, 2007.
Velcro[registered sign] nonlinear mechanics
Nicola Maria Pugno
In this letter a Velcro[registered sign] nonlinear mechanics is presented. In particular, a calculation of the elastic strength of hooks with friction is derived. The author quantifies, as the intuition and Velcro[registered sign] material suggest, that hooks (and loops) allow reversible strong atta ... [Appl. Phys. Lett. 90, 121918 (2007)] published Thu Mar 22, 2007.
Competition and cooperation between lattice-oriented growth and step-templated growth of aligned carbon nanotubes on sapphire
Hiroki Ago, Kenta Imamoto, Naoki Ishigami, Ryota Ohdo, Ken-ichi Ikeda et al.
The authors study the growth mechanism of single-walled carbon nanotubes (SWNTs) horizontally aligned on A-plane single crystal sapphire (11[overline 2]0) by making the controlled step/terrace structure. SWNT growth direction was sensitive to the surface geometry of the sapphire, and there was compe ... [Appl. Phys. Lett. 90, 123112 (2007)] published Thu Mar 22, 2007.
Generalized phase-shifting interferometry with arbitrary unknown phase shifts: Direct wave-front reconstruction by blind phase shift extraction and its experimental verification
X. F. Xu, L. Z. Cai, Y. R. Wang, X. L. Yang, X. F. Meng et al.
A simple wave-front reconstruction method by generalized phase-shifting interferometry (PSI) with arbitrary unknown phase shift between 0 and pi for two adjacent frames is proposed. In this method the unknown phase shifts are extracted by a noniterative algorithm with the use of the interferograms a ... [Appl. Phys. Lett. 90, 121124 (2007)] published Thu Mar 22, 2007.
Nonresonant electrical injection of excitons in an InGaAs quantum well
D. Bajoni, A. Miard, A. Lemaitre, S. Bouchoule, J. Bloch et al.
The authors report on electroluminescence measurements combined with photoluminescence excitation spectroscopy on a single InGaAs quantum well placed in the intrinsic region of a p-i-n photodiode. They show that at low current density, the spectra are dominated by the spectrally narrow excitonic emi ... [Appl. Phys. Lett. 90, 121114 (2007)] published Wed Mar 21, 2007.
Study of self-diffraction process in photoconducting polymer-nematic liquid crystal hybrid structure
Jaroslaw Mysliwiec, Dorota Jarzab, Krzysztof Janus, and Stanislaw Bartkiewicz
The authors present results of the measurements of self-diffraction process inside the nematic liquid crystal cell with a photoconducting polymeric layer poly(N-vinylcarbazole) doped with trinitrofluorenone molecules. The dynamics of diffraction grating fading process versus applied voltage and diff ... [Appl. Phys. Lett. 90, 121120 (2007)] published Wed Mar 21, 2007.
Optical properties of dilute nitrogen GaInNAs quantum dots
Stanko Tomić
The authors present a theoretical study of the ground state optical transition matrix element in quantum dots (QDs) with a dilute amount of nitrogen. They have investigated the interplay between the nitrogen to the conduction band mixing and piezoelectric field on the optical matrix element. With a ... [Appl. Phys. Lett. 90, 121115 (2007)] published Wed Mar 21, 2007.
Self-assembled periodic nanoporous network in multifunctional ZrO[sub 2]--CeO[sub 2]--(La[sub 0.8]Sr[sub 0.2])MnO[sub 3] composites
Vaneet Sharma, Jiechao Jiang, Maria Hossu, Ali R. Koymen, and Shashank Priya
This letter reports the structural characteristics of the self-assembled surface nanostructure in the 0.75 wt % (Zr[sub 0.88]Ce[sub 0.12])O[sub 2]0.25 wt % (La[sub 0.8]Sr[sub 0.2])MnO[sub 3] ceramics. The surface consists of periodic porous network with islandlike structures occurring at the tri ... [Appl. Phys. Lett. 90, 123110 (2007)] published Wed Mar 21, 2007.
High quality AlGaN solar-blind Schottky photodiodes fabricated on AIN/sapphire template
H. Jiang and T. Egawa
The authors report the high-performance AlGaN solar-blind Schottky photodiodes grown on AIN/sapphire templates by metal organic chemical vapor deposition. The devices exhibit dark current densities as low as 1.6 x 10[sup 11] A/cm[sup 2] at 5 V bias. The peak responsivity is 41 mA/W at 256 nm in ... [Appl. Phys. Lett. 90, 121121 (2007)] published Wed Mar 21, 2007.
Direct evidence of an order-disorder nature of ferroelectric phase transitions in K[sub 2]MgWO[sub 2](PO[sub 4])[sub 2]
Miroslaw Maczka, Jerzy Hanuza, Andrzej Majchrowski, and Seiji Kojima
K[sub 2]MgWO[sub 2](PO[sub 4])[sub 2] single crystal, related to famous optical nonlinear material KTiOPO[sub 4], was investigated by micro-Brillouin scattering with a focus on the central components of the relaxation modes. A critical slowing down has been clearly observed in the vicinity of T[sub ... [Appl. Phys. Lett. 90, 122903 (2007)] published Wed Mar 21, 2007.
Isotropic photonic magnetoresistance
K. J. Chau, C. A. Baron, and A. Y. Elezzabi
The authors demonstrate isotropic photonic magnetoresistive behavior in the far-infrared transmission through ferromagnetic particle collections. Total suppression of the angular anisotropy, a fundamental characteristic of anisotropic magnetoresistance, is achieved in ensembles of highly porous, cau ... [Appl. Phys. Lett. 90, 121122 (2007)] published Wed Mar 21, 2007.
Defect-mediated surface morphology of nonpolar m-plane GaN
A. Hirai, B. A. Haskell, M. B. McLaurin, F. Wu, M. C. Schmidt et al.
The role of extended defects in determining the atomic scale surface morphology of nonpolar {1[overline 1]00} m-plane gallium nitride has been elucidated. The heteroepitaxially grown m-GaN films are commonly reported to yield striated surface morphologies (slate morphology) correlated with their hig ... [Appl. Phys. Lett. 90, 121119 (2007)] published Wed Mar 21, 2007.
Highly efficient and stable red phosphorescent organic light-emitting device using bis[2-(2-benzothiazoyl)phenolato]zinc(II) as host material
Hiroshi Kanno, Kaori Ishikawa, Yoshitaka Nishio, Ayataka Endo, Chihaya Adachi et al.
The red-emitting phosphorescent organic light-emitting device employing Bis[2-(2-benzothiazoyl)phenolato]zinc(II) (Zn(BTP)[sub 2]) as a host material has been demonstrated. The device generates saturated red emission with Commission Internationale de l'Eclairage coordinates of (0.67, 0.33), characte ... [Appl. Phys. Lett. 90, 123509 (2007)] published Wed Mar 21, 2007.
Wafer-level microelectromechanical system structural material test by electrical signal before pull-in
Yuh-Chung Hu and Po-Yuan Huang
The letter develops a wafer-level testing method to examine Young's modulus and residual stress of structural material of capacitive microdevice by measuring the pre-pull-in capacitance variation of the microtest beam made of the material to be tested. The required instrument is only a precision LCR ... [Appl. Phys. Lett. 90, 121908 (2007)] published Wed Mar 21, 2007.
Identification of modes and single mode operation of sapphire-bonded photonic crystal lasers under continuous-wave room temperature operation
M. H. Shih, Mahmood Bagheri, Adam Mock, S. J. Choi, J. D. O'Brien et al.
Sapphire-bonded photonic crystal laser cavities were fabricated and characterized under room temperature continuous-wave operation, and the single mode lasing with a side-mode-suppression ratio of 28 dB was observed. The lasing modes of the photonic crystal cavities were characterized and compared ... [Appl. Phys. Lett. 90, 121116 (2007)] published Wed Mar 21, 2007.
Observation of protein-protein interaction by dielectric relaxation spectroscopy of protein solutions for biosensor application
Brian A. Mazzeo and Andrew J. Flewitt
Dielectric spectroscopy was used to measure the dielectric relaxation of bovine serum albumin, Protein A, and rabbit IgG in solution. Measurements were performed with an impedance analyzer and dielectric cell. Protein additions to bulk solution were measured by differential dielectric relaxation spe ... [Appl. Phys. Lett. 90, 123901 (2007)] published Wed Mar 21, 2007.
Role of gross well-width fluctuations in bright, green-emitting single InGaN/GaN quantum well structures
Nicole K. van der Laak, Rachel A. Oliver, Menno J. Kappers, and Colin J. Humphreys
Gross well-width fluctuations have been observed by transmission electron microscopy (TEM) in single InGaN/GaN quantum wells (QWs) grown by metal-organic vapor phase epitaxy. Similar thickness variations are observed in commercial, green InGaN/GaN multi-QW light emitting diodes. Atomic force microsc ... [Appl. Phys. Lett. 90, 121911 (2007)] published Wed Mar 21, 2007.
Time-to-space mapping in a gas medium for the temporal characterization of vacuum-ultraviolet pulses
S. Cunovic, N. Muller, R. Kalms, M. Krikunova, M. Wieland et al.
The authors introduce a method for cross correlating vacuum-ultraviolet with near-infrared femtosecond light pulses in a perpendicular geometry. Photoelectrons generated in an atomic gas by laser-assisted photoionization are used to create a two-dimensional image of the cross-correlation volume, the ... [Appl. Phys. Lett. 90, 121112 (2007)] published Wed Mar 21, 2007.
Correlation between electron and negative O[sup -] ion emission during reactive sputtering of oxides
S. Mahieu and D. Depla
The energy distribution of negative O[sup ] ions has been measured during the reactive magnetron sputtering of 13 different target materials by the means of energy resolved mass spectrometry. For the same series of target materials the ion-induced secondary electron emission coefficient was determin ... [Appl. Phys. Lett. 90, 121117 (2007)] published Wed Mar 21, 2007.
Two-photon absorption in quantum dots based on a nonconjugated conductive polymer
Jitto Titus and M. Thakur
Two-photon absorption has been measured in a nano-optical material (quantum dots) based on the nonconjugated conductive polymer, iodine-doped poly(beta-pinene). The measurement has been made using open-aperture z scan at 730860 nm with 150 fs pulses. Exceptionally large two-photon absorption coeff ... [Appl. Phys. Lett. 90, 121111 (2007)] published Wed Mar 21, 2007.
Effect of ionization rates on dynamic recovery processes during electron-beam irradiation of 6H-SiC
In-Tae Bae, William J. Weber, Manabu Ishimaru, and Yoshihiko Hirotsu
The authors have investigated the effects of 200 and 300 keV electron-beam irradiations on amorphization in 6H-SiC at 100 and 295 K. Amorphization is induced by the accumulation of defects produced by direct atomic displacements. Dynamic recovery of these defects during irradiation, due to tempera ... [Appl. Phys. Lett. 90, 121910 (2007)] published Wed Mar 21, 2007.
Infrared lasing in InN nanobelts
Ming-Shien Hu, Geng-Ming Hsu, Kuei-Hsien Chen, Chia-Ju Yu, Hsu-Cheng Hsu et al.
Infrared lasing from single-crystalline InN nanobelts grown by metal organic chemical vapor deposition was demonstrated. Transmission electron microscopy studies revealed that the InN nanobelts of rectangular cross section grew along [110] direction and were enclosed by (001) and (1[overline 1]0) pl ... [Appl. Phys. Lett. 90, 123109 (2007)] published Wed Mar 21, 2007.
Liquid-crystal-based linear polarization rotator
Hongwen Ren and Shin-Tson Wu
A liquid-crystal (LC)-based polarization rotator which can rotate the polarization axis of an incident linearly polarized light from 0 degrees to 90 degrees is demonstrated. In the LC cell, the top substrate has a uniform rubbing but the bottom substrate has two orthogonal rubbings which are separ ... [Appl. Phys. Lett. 90, 121123 (2007)] published Wed Mar 21, 2007.
Crystalline ZnO with an enhanced surface area obtained by nanocasting
T. Waitz, M. Tiemann, P. J. Klar, J. Sann, J. Stehr et al.
The authors report the synthesis of nanoporous ZnO, which exhibits a periodically ordered, uniform pore system with crystalline pore walls. The crystalline structure is investigated by x-ray diffraction, transmission electron microscopy, and selected area electron diffraction. The large specific sur ... [Appl. Phys. Lett. 90, 123108 (2007)] published Wed Mar 21, 2007.
Dynamics of a two-state quantum dot laser with saturable absorber
E. A. Viktorov, M. A. Cataluna, L. O'Faolain, T. F. Krauss, W. Sibbett et al.
The authors study the regime of self-pulsations in a two-state quantum dot laser with saturable absorber. Experiments demonstrate and theory explains the appearance of self-pulsations at low relaxation oscillation frequency. The system exhibits a period doubling sequence of bifurcations leading to c ... [Appl. Phys. Lett. 90, 121113 (2007)] published Wed Mar 21, 2007.
Modified efficient cluster packing model for calculating alloy compositions with high glass forming ability
A. P. Wang, J. Q. Wang, and E. Ma
The efficient cluster packing model for bulk metallic glasses (BMGs) has been modified and extended to allow quantitative predictions of alloy compositions with high glass forming ability. The compositions calculated using this simple method compare favorably with the vast majority of the BMGs disco ... [Appl. Phys. Lett. 90, 121912 (2007)] published Wed Mar 21, 2007.
Fabrication and device characteristics of Schottky-type bulk GaN-based ``visible-blind'' ultraviolet photodetectors
Yi Zhou, Claude Ahyi, Chin-Che Tin, John Williams, Minseo Park et al.
The authors present the fabrication and characterization of vertical-geometry Schottky-type ultraviolet (UV) photodetectors based on a bulk n-GaN substrate. By using low temperature rapid thermal annealing of the semitransparent Schottky contacts (nickel with 7% vanadium), they obtained an ultralow ... [Appl. Phys. Lett. 90, 121118 (2007)] published Wed Mar 21, 2007.
Phase transition of ultrathin AlN interlayer at AlGaN/GaN interface
Duanjun Cai and Junyong Kang
The authors report the wurtizite to zinc-blende phase transition of ultrathin AlN interlayer at the interface of AlGaN/GaN. The shape transformation of the pinhole from hexagon to dodecagon exhibits the structural transition of the interfacial layer, where exists an AlN segregation interlayer. By tr ... [Appl. Phys. Lett. 90, 121909 (2007)] published Wed Mar 21, 2007.
Reflection properties of hybrid quarter-wavelength silicon microstructures
Giuseppe Barillaro, Valerio Annovazzi-Lodi, Mauro Benedetti, and Sabina Merlo
The authors present experimental and numerical results relative to the polarization-resolved spectral reflectivity of one-dimensional periodic microstructures, evaluated in the near-infrared region at non-normal incidence. The tested hybrid quarter-wavelength microstructures, fabricated by electroch ... [Appl. Phys. Lett. 90, 121110 (2007)] published Wed Mar 21, 2007.
Erratum: ``Atomically resolved structure of InAs quantum dots'' [Appl. Phys. Lett. [bold 78], 2309 (2001)]
H. Eisele and K. Jacobi
... [Appl. Phys. Lett. 90, 129902 (2007)] published Tue Mar 20, 2007.
Resistance switching of copper doped MoO[sub x] films for nonvolatile memory applications
Dongsoo Lee, Dong-jun Seong, Inhwa Jo, F. Xiang, R. Dong et al.
Nonvolatile and reversible resistance switching of copper doped MoO[sub x] film was studied. Hysteretic-type resistive switching was observed under dc. Reproducible resistance switching over 10[sup 6] cycles was observed under alternative voltage pulses. Two resistance states can be maintained for ... [Appl. Phys. Lett. 90, 122104 (2007)] published Tue Mar 20, 2007.
Impacts of a polycrystalline-silicon buffer layer on the performance and reliability of strained n-channel metal-oxide-semiconductor field-effect transistors with SiN capping
Ching-Sen Lu, Horng-Chih Lin, Jian-Ming Huang, and Yao-Jen Lee
Characteristics of n-channel metal-oxide-semiconductor field-effect transistors with SiN capping were investigated in this work. Although the SiN capping could dramatically enhance the carrier mobility and thus the device drive current, the resistance to hot-carrier degradation is compromised as wel ... [Appl. Phys. Lett. 90, 122110 (2007)] published Tue Mar 20, 2007.
Air-stable ambipolar organic transistors
Thomas D. Anthopoulos, G. C. Anyfantis, G. C. Papavassiliou, and Dago M. de Leeuw
The authors report on ambipolar organic transistors based on the soluble dithiolene derivative (diphenylethylenedithiolato)(1,3-dithiol-2-thione-4,5-dithiolato)nickel [Ni(dpedt)(dmit)]. Due to its small band gap, efficient injection of holes and electrons from gold source/drain electrodes is possibl ... [Appl. Phys. Lett. 90, 122105 (2007)] published Tue Mar 20, 2007.
Nucleation switching in phase change memory
V. G. Karpov, Y. A. Kryukov, S. D. Savransky, and I. V. Karpov
The authors propose a simple physical model of threshold switching in phase change memory cells based on the field induced nucleation of conductive cylindrical crystallites. The model is solved analytically and leads to a number of predictions including correlations between the threshold voltage V[s ... [Appl. Phys. Lett. 90, 123504 (2007)] published Tue Mar 20, 2007.
Efficiency of composite boron nitride neutron detectors in comparison with helium-3 detectors
J. Uher, S. Pospisil, V. Linhart, and M. Schieber
It has been clearly demonstrated that the composite boron nitride (BN) semiconductor polycrystalline bulk detectors with BN grains embedded in a polymer matrix operate as an effective detector of thermal neutrons even if they contain natural boron only. A reasonable signal to noise ratio has been ac ... [Appl. Phys. Lett. 90, 124101 (2007)] published Tue Mar 20, 2007.
Nonvolatile polycrystalline silicon thin-film-transistor memory with oxide/nitride/oxide stack gate dielectrics and nanowire channels
Shih-Ching Chen, Ting-Chang Chang, Po-Tsun Liu, Yung-Chun Wu, Ping-Hung Yeh et al.
In this work, the authors study a polycrystalline silicon thin-film transistor (poly-Si TFT) with oxide/nitride/oxide (ONO) stack gate dielectrics and multiple nanowire channels for the applications of both nonvolatile silicon-oxide-nitride-oxide-silicon (SONOS) memory and switch transistor. The pro ... [Appl. Phys. Lett. 90, 122111 (2007)] published Tue Mar 20, 2007.
Near field distribution in two dimensionally arrayed gold nanoparticles on platinum substrate
Nikolay Nedyalkov, Tetsuo Sakai, Tomoya Miyanishi, and Minoru Obara
Theoretical and experimental results for near field properties in the vicinity of two dimensionally aligned gold nanoparticles are presented. The numerical analysis is based on finite difference time domain simulation code. The simulated system consists of gold particles with a radius of 100 nm, de ... [Appl. Phys. Lett. 90, 123106 (2007)] published Tue Mar 20, 2007.
c-axis correlated pinning behavior near the irreversibility fields
Satoshi Awaji, Masafumi Namba, Kazuo Watanabe, Masashi Miura, Yutaka Yoshida et al.
The authors found that the peak at the parallel external field (B||c) to the c axis in the angular dependence of J[sub c] shrinks and almost disappears with increasing a magnetic field but it grows again with further increasing of a magnetic field at various temperatures for high-J[sub c] Sm[sub 1+x ... [Appl. Phys. Lett. 90, 122501 (2007)] published Tue Mar 20, 2007.
Resonant tunneling diode with spin polarized injector
A. Slobodskyy, C. Gould, T. Slobodskyy, G. Schmidt, L. W. Molenkamp et al.
The authors investigate the current-voltage characteristics of a II-VI semiconductor resonant tunneling diode coupled to a diluted magnetic semiconductor injector. As a result of an external magnetic field, a giant Zeeman splitting develops in the injector, which modifies the band structure of the d ... [Appl. Phys. Lett. 90, 122109 (2007)] published Tue Mar 20, 2007.
Single Schottky-barrier photodiode with interdigitated-finger geometry: Application to diamond
Meiyong Liao, Yasuo Koide, and Jose Alvarez
The authors propose a single Schottky-barrier photodiode (SPD) with interdigitated Ohmic and Schottky contacts. A homoepitaxial diamond layer with low boron concentration has been utilized as an example for the fabrication of solar-blind deep-ultraviolet detector. This device structure enables the o ... [Appl. Phys. Lett. 90, 123507 (2007)] published Tue Mar 20, 2007.
Anomalous behavior of AlGaN/GaN heterostructure field-effect transistors at cryogenic temperatures: From current collapse to current enhancement with cooling
H. F. Sun and C. R. Bolognesi
While current collapse affects AlGaN/GaN heterojunction field-effect transistors (HFETs) around room temperature, it gradually gives place to a current enhancement with coolingbelow 200 K, electrically stressed devices do show higher currents than in their prestressed state. This behavior can be ex ... [Appl. Phys. Lett. 90, 123505 (2007)] published Tue Mar 20, 2007.
Properties of Ga[sub 1 - x]Mn[sub x]As with high Mn composition (x > 0.1)
D. Chiba, Y. Nishitani, F. Matsukura, and H. Ohno
A series of Ga[sub 1x]Mn[sub x]As layers with high Mn compositions x (=0.0750.200) has been grown and investigated. Magnetization, magnetotransport, and magneto-optical properties reveal that the layers have single ferromagnetic phase as in the case of typical (Ga,Mn)As. The authors also describe th ... [Appl. Phys. Lett. 90, 122503 (2007)] published Tue Mar 20, 2007.
Enhanced charge-discharge characteristics of RuO[sub 2] supercapacitors on heat-treated TiO[sub 2] nanorods
Young Rack Ahn, Chong Rae Park, Seong Mu Jo, and Dong Young Kim
Electrochemical capacitors based on RuO[sub 2] were prepared onto electrospun TiO[sub 2] nanorods. Further heat treatment of the TiO[sub 2] at 800 degrees C under nitrogen was found to greatly improve the electrochemical performance of the RuO[sub 2] electrodes, especially at fast charge-discharge ... [Appl. Phys. Lett. 90, 122106 (2007)] published Tue Mar 20, 2007.
High-efficiency deep blue host for organic light-emitting devices
Zhi Qiang Gao, Bao Xiu Mi, Chin H. Chen, Kow Wai Cheah, Yuen Kit Cheng et al.
High-efficiency deep blue organic light-emitting devices have been fabricated using asymmetrically substituted 9-(alpha-naphthyl)-10-(beta-naphthyl)-anthracene as blue host material and diphenyl-[4-(2-[1,1[sup [prime]];4[sup [prime]],1[sup [double-prime]]]terphenyl-4-yl-vinyl)-phenyl]amine as dopant ... [Appl. Phys. Lett. 90, 123506 (2007)] published Tue Mar 20, 2007.
Nanoscale x-ray magnetic circular dichroism probing of electric-field-induced magnetic switching in multiferroic nanostructures
T. Zhao, A. Scholl, F. Zavaliche, H. Zheng, M. Barry et al.
The magnetic structure as well as its response to an external electric field were studied in ferrimagnetic CoFe[sub 2]O[sub 4] nanopillars embedded in an epitaxial ferroelectric BiFeO[sub 3] film using photoemission electron microscopy and x-ray magnetic circular dichroism. Magnetic switching was ob ... [Appl. Phys. Lett. 90, 123104 (2007)] published Tue Mar 20, 2007.
Schottky ultraviolet photodiode using a ZnO hydrothermally grown single crystal substrate
Haruyuki Endo, Mayo Sugibuchi, Kousuke Takahashi, Shunsuke Goto, Shigeaki Sugimura et al.
A Schottky ultraviolet photodiode using a (0001) ZnO single crystal grown by the hydrothermal growth method is reported. The photodiode consisted of a semitransparent Pt film for the Schottky electrode and an Al thin film for the Ohmic electrode. The photodiode had polarity dependences on current-vo ... [Appl. Phys. Lett. 90, 121906 (2007)] published Tue Mar 20, 2007.
Zeeman splitting in ballistic GaInAs/InP split-gate quantum point contacts
Th. Schapers, V. A. Guzenko, and H. Hardtdegen
The Zeeman splitting in ballistic Ga[sub x]In[sub 1x]As/InP split-gate point contacts was investigated. The measurements were performed in a magnetic field perpendicular to the plane of the two-dimensional electron gas. The Zeeman energy splitting between the one-dimensional subbands was determined ... [Appl. Phys. Lett. 90, 122107 (2007)] published Tue Mar 20, 2007.
Experimental investigation of the lattice and electronic temperatures in Ga[sub 0.47]In[sub 0.53]As/Al[sub 0.62]Ga[sub 0.38]As[sub 1 - x]Sb[sub x] quantum-cascade lasers
Miriam S. Vitiello, Gaetano Scamarcio, Vincenzo Spagnolo, Antonia Lops, Quankui Yang et al.
The authors extracted the thermal resistance (R[sub L]=9.6 K/W) and the electrical power dependence of the electronic temperature (R[sub e]=12.5 K/W) of Ga[sub 0.47]In[sub 0.53]As/Al[sub 0.62]Ga[sub 0.38]As[sub 1x]Sb[sub x] quantum-cascade lasers (QCLs) operating at 4.9 [mu]m, in the lattice temp ... [Appl. Phys. Lett. 90, 121109 (2007)] published Tue Mar 20, 2007.
Interface dominated biferroic La[sub 0.6]Sr[sub 0.4]MnO[sub 3]/0.7Pb(Mg[sub 1/3]Nb[sub 2/3])O[sub 3]--0.3PbTiO[sub 3] epitaxial superlattices
Ayan Roy Chaudhuri, R. Ranjith, S. B. Krupanidhi, R. V. K. Mangalam, and A. Sundaresan
Superlattices composed of ferromagnetic La[sub 0.6]Sr[sub 0.4]MnO[sub 3] and ferroelectric 0.7Pb(Mg[sub 1/3]Nb[sub 2/3])O[sub 3]0.3(PbTiO[sub 3]) layers were fabricated on (100) LaAlO[sub 3] substrates by pulsed laser deposition technique. The ferromagnetic and frequency independent ferroelectric hy ... [Appl. Phys. Lett. 90, 122902 (2007)] published Tue Mar 20, 2007.
Effects of molecular oxygen and ozone on polythiophene-based thin-film transistors
Michael L. Chabinyc, Robert A. Street, and John E. Northrup
The effects of exposure of polymeric thin-film transistors (TFTs) to the ambient atmosphere, oxygen, and ozone were investigated. The off-state current increased and the threshold voltage became more positive for TFTs made with several thiophene-based polymers when exposed to the ambient. Exposure t ... [Appl. Phys. Lett. 90, 123508 (2007)] published Tue Mar 20, 2007.
Highly stable three-band white light from an InGaN-based blue light-emitting diode chip precoated with (oxy)nitride green/red phosphors
Chih-Chieh Yang, Chih-Min Lin, Yi-Jung Chen, Yi-Tsuo Wu, Shih-Ren Chuang et al.
A three-band white light-emitting diode (LED) was fabricated using an InGaN-based blue LED chip that emits 455 nm blue light, and green phosphor SrSi[sub 2]O[sub 2]N[sub 2]:Eu and red phosphor CaSiN[sub 2]:Ce that emit 538 nm green and 642 nm red emissions, respectively, when excited by the 455 ... [Appl. Phys. Lett. 90, 123503 (2007)] published Tue Mar 20, 2007.
On-chip electron-impact ion source using carbon nanotube field emitters
Christopher A. Bower, Kristin H. Gilchrist, Jeffrey R. Piascik, Brian R. Stoner, Srividya Natarajan et al.
A lateral on-chip electron-impact ion source utilizing a carbon nanotube field emission electron source was fabricated and characterized. The device consists of a cathode with aligned carbon nanotubes, a control grid, and an ion collector electrode. The electron-impact ionization of He, Ar, and Xe w ... [Appl. Phys. Lett. 90, 124102 (2007)] published Tue Mar 20, 2007.
Effect of processing temperature on high field critical current density and upper critical field of nanocarbon doped MgB[sub 2]
W. K. Yeoh, J. Horvat, J. H. Kim, X. Xu, and S. X. Dou
Correlation of upper critical field (H[sub c2]) and critical current density (J[sub c]) with processing temperature of nano-C doped MgB[sub 2] has been studied in comparison to SiC and pure MgB[sub 2]. SiC and C doped MgB[sub 2] exhibit opposite trends in the dependence of J[sub c] and H[sub c2] on ... [Appl. Phys. Lett. 90, 122502 (2007)] published Tue Mar 20, 2007.
Three-dimensional carbon nanowall structures
Alfred T. H. Chuang, John Robertson, Bojan O. Boskovic, and Krzysztof K. K. Koziol
The authors report the growth of carbon nanowalls in freestanding, three-dimensional aggregates by microwave plasma-enhanced chemical vapor deposition. Carbon nanowalls extrude from plasma sites into three-dimensional space. The growth is catalyst-free and not limited by nucleating surfaces. The gro ... [Appl. Phys. Lett. 90, 123107 (2007)] published Tue Mar 20, 2007.
Microstructure analysis of c-axis oriented aluminum nitride thin films by high-resolution transmission electron microscopy
Z. Q. Yao, Q. Ye, Y. Q. Li, Y. S. Zou, W. J. Zhang et al.
The microstructure, in particular, the surface and interface regions, of the c-axis orientated AlN films deposited on Si (100) substrates was studied. The films showed an evolutionary columnar growth process. In contrast to the previous reports, high-resolution transmission electron microscopy revea ... [Appl. Phys. Lett. 90, 121907 (2007)] published Tue Mar 20, 2007.
Chip cooling with integrated carbon nanotube microfin architectures
K. Kordas, G. Toth, P. Moilanen, M. Kumpumaki, J. Vahakangas et al.
Efficient cooling of silicon chips using microfin structures made of aligned multiwalled carbon nanotube arrays is achieved. The tiny cooling elements mounted on the back side of the chips enable power dissipation from the heated chips on the level of modern electronics demands. The nanotube fins ar ... [Appl. Phys. Lett. 90, 123105 (2007)] published Tue Mar 20, 2007.
Erratum: ``Interlayer coupling in ferromagnetic epitaxial Fe[sub 3]Si/FeSi[sub 2] superlattices'' [Appl. Phys. Lett. [bold 89], 253110 (2006)]
T. Yoshitake, T. Ogawa, D. Nakagauchi, D. Hara, M. Itakura et al.
... [Appl. Phys. Lett. 90, 129901 (2007)] published Tue Mar 20, 2007.
Carrier capture dynamics of InAs/GaAs quantum dots
T. Piwonski, I. O'Driscoll, J. Houlihan, G. Huyet, R. J. Manning et al.
Carrier dynamics of a 1.3 [mu]m InAs/GaAs quantum dot amplifier is studied using heterodyne pump-probe spectroscopy. Measurements of the recovery times versus injection current reveal a power law behavior predicted by a quantum dot rate equation model. These results indicate that Auger processes do ... [Appl. Phys. Lett. 90, 122108 (2007)] published Tue Mar 20, 2007.
Effects of plasma immersion ion nitridation on dielectric properties of HfO[sub 2]
L. Wang, K. Xue, J. B. Xu, A. P. Huang, and Paul K. Chu
Plasma immersion ion nitridation is used to produce thin HfO[sub 2] films with improved thermal and electrical properties. The film composition is investigated by examining the chemical shifts of the Hf 4f, Si 2p, and N 1s core-level spectra using x-ray photoelectron spectroscopy. The improved therm ... [Appl. Phys. Lett. 90, 122901 (2007)] published Tue Mar 20, 2007.
Method to improve the quality of acousto-optic imaging using an ultrashort and focused ultrasound pulse
Cuncheng Weng
The letter shows that the optical scattering and the length of ultrasound-wave train are key factors affecting the quality of acousto-optic imaging. A method using an ultrashort and focused ultrasound pulse is provided. The method has the potential to improve the quality of acousto-optic imaging. ... [Appl. Phys. Lett. 90, 121108 (2007)] published Tue Mar 20, 2007.
Aligned AlN nanowires and microrods by self-patterning
G. R. Yazdi, M. Syvajarvi, and R. Yakimova
Self-patterned AlN microrods and nanowires were grown on 4H-SiC substrate by a physical vapor transport method. AlN hexagonal pyramids were found to be nucleation sites for the evolution of the observed morphological forms. The average diameter and length of the nanowires are about 200 nm and 90 [ ... [Appl. Phys. Lett. 90, 123103 (2007)] published Mon Mar 19, 2007.
Effects of carbon nanotubes on electro-optical characteristics of liquid crystal cell driven by in-plane field
Sang Youn Jeon, Seung Hwan Shin, Seok Jin Jeong, Seung Hee Lee, Seok Ho Jeong et al.
Homogeneously aligned nematic liquid crystal (LC) cells doped with carbon nanotubes (CNTs) driven by an in-plane field were fabricated and their electro-optic characteristics were investigated. The effective cell retardation values showed no difference between doped and undoped LC cells in the absen ... [Appl. Phys. Lett. 90, 121901 (2007)] published Mon Mar 19, 2007.
Enhanced photoinduced birefringence in polymer-dye complexes: Hydrogen bonding makes a difference
Arri Priimagi, Matti Kaivola, Francisco J. Rodriguez, and Martti Kauranen
The authors demonstrate that photoinduced birefringence in azo-dye-doped polymers is strongly enhanced by hydrogen bonding between the guest molecules and the polymer host. The primary mechanism behind the enhancement is the possibility to use high dye doping levels compared to conventional guest-ho ... [Appl. Phys. Lett. 90, 121103 (2007)] published Mon Mar 19, 2007.
Predictions of thermoelastic stress in a broad-area semiconductor laser
B. P. Cox and W. R. Smith
The coupling of electrical, optical, and thermal effects in broad-area semiconductor lasers has been investigated using a multilateral mode mathematical model. Numerical solutions for the active layer temperature rise are input into the thermal source terms of elasticity equations, leading to the pr ... [Appl. Phys. Lett. 90, 121105 (2007)] published Mon Mar 19, 2007.
Heteroepitaxial growth of sixfold symmetric osmium on Si (111) and Si (100)
Tai-Yen Peng, C. K. Lo, Y. D. Yao, and San-Yuan Chen
Growing sixfold symmetric osmium (Os) epitaxial films with suitable buffer layers was developed. Using a Cu buffer layer, the lattice mismatch between Os (0002) and Si (100) was significantly reduced from >30% to ~7% to grow Os films with twin relationships and weak sixfold symmetries. On the other ... [Appl. Phys. Lett. 90, 121904 (2007)] published Mon Mar 19, 2007.
Short wavelength (lambda = 2.13 mu m) intersubband luminescence from GaN/AlN quantum wells at room temperature
L. Nevou, M. Tchernycheva, F. H. Julien, F. Guillot, and E. Monroy
The authors report the observation of room-temperature intersubband luminescence at lambda=2.13 [mu]m from GaN/AlN quantum wells under optical pumping at lambda=0.98 [mu]m. The quantum wells are designed to exhibit three bound states in the conduction band. The emission arises from the e[sub 3]e[s ... [Appl. Phys. Lett. 90, 121106 (2007)] published Mon Mar 19, 2007.
Plasmonic excitation of organic double heterostructure solar cells
J. K. Mapel, M. Singh, M. A. Baldo, and K. Celebi
The authors demonstrate that thin film organic photovoltaic cells are efficient detectors of surface plasmon polaritons (SPPs). For lambda=532 nm radiation in a Kretschmann configuration, the external quantum efficiency in fullerenecopper phthalocyanine photovoltaic cells is doubled at resonance to ... [Appl. Phys. Lett. 90, 121102 (2007)] published Mon Mar 19, 2007.
Winding of single-walled carbon nanotube ropes: An effective load transfer
Tung-Wen Cheng and Wen-Kuang Hsu
The strength of single-walled carbon nanotube ropes is enhanced by a factor of 6 via a winding procedure. A stepwise structure seen at a load-strain profile is explained based on an intermittent fracture mechanism. ... [Appl. Phys. Lett. 90, 123102 (2007)] published Mon Mar 19, 2007.
Anomalous thermal stability of cubic tin confined in a nanotube
B. Wang, G. Ouyang, Y. H. Yang, and G. W. Yang
In situ observations of transmission electron microscopy have indicated that the cubic Sn phase confined in a nanotube has extreme stability even when the temperature is more than 700 degrees C, significantly higher than the melting point (231.9 degrees C) of tin. A thermodynamic model was estab ... [Appl. Phys. Lett. 90, 121905 (2007)] published Mon Mar 19, 2007.
Observation of negative bias stressing interface trapping centers in metal gate hafnium oxide field effect transistors using spin dependent recombination
C. J. Cochrane, P. M. Lenahan, J. P. Campbell, G. Bersuker, and A. Neugroschel
The authors combine metal oxide semiconductor (MOS) gated diode measurements and very sensitive electrically detected electron spin resonance measurements to detect and identify negative bias temperature instability (NBTI) generated defect centers in fully processed HfO[sub 2] pMOS field effect tran ... [Appl. Phys. Lett. 90, 123502 (2007)] published Mon Mar 19, 2007.
High-pressure and high-temperature annealing as an activation method for ion-implanted dopants in diamond
K. Ueda, M. Kasu, and T. Makimoto
The authors show that high-pressure and high-temperature (HPHT) annealing is very effective for the activation of ion-implanted dopants in diamond. The HPHT annealing condition is located in the thermodynamically stable region for diamond in the phase diagram and is, therefore, much more efficient f ... [Appl. Phys. Lett. 90, 122102 (2007)] published Mon Mar 19, 2007.
Hydrogen peroxide treatment induced rectifying behavior of Au/n-ZnO contact
Q. L. Gu, C. C. Ling, X. D. Chen, C. K. Cheng, A. M. C. Ng et al.
Conversion of the Au/n-ZnO contact from Ohmic to rectifying with H[sub 2]O[sub 2] pretreatment was studied systematically using I-V measurements, x-ray photoemission spectroscopy, positron annihilation spectroscopy, and deep level transient spectroscopy. H[sub 2]O[sub 2] treatment did not affect the ... [Appl. Phys. Lett. 90, 122101 (2007)] published Mon Mar 19, 2007.
Polarized optical feedback from an extremely short external cavity for controlling and stabilizing the polarization of vertical cavity surface emitting lasers
Mikel Arizaleta Arteaga, Olivier Parriaux, Manuel Lopez-Amo, Hugo Thienpont, and Krassimir Panajotov
The authors present experimental results showing that polarization selective optical feedback from an extremely short external cavity induces switching between the two fundamental transverse modes with orthogonal linear polarization of the otherwise (without optical feedback) polarization stable ver ... [Appl. Phys. Lett. 90, 121104 (2007)] published Mon Mar 19, 2007.
Symmetry properties and anisotropic excitonic response for GaN films grown on semipolar (11 - 22)-, (10 - 11)-, and (10 - 13)-oriented GaN substrates
Bernard Gil
The author analyzes the optical properties of GaN homoepitaxies grown on semipolar (112x)- and (101x)-oriented GaN substrates. He works here in the specific cases of (1122)-, (1011)-, and (1013)-orientations which currently deserve intense experimental activity. The author finds the optical anisotro ... [Appl. Phys. Lett. 90, 121903 (2007)] published Mon Mar 19, 2007.
Deep level defects which limit current gain in 4H SiC bipolar junction transistors
C. J. Cochrane, P. M. Lenahan, and A. J. Lelis
The authors employ a very sensitive electrically detected electron spin resonance technique called spin dependent recombination to observe recombination centers in fully processed 4H SiC n-p-n bipolar junction transistors. Their measurements indicate that the observed dominating recombination defect ... [Appl. Phys. Lett. 90, 123501 (2007)] published Mon Mar 19, 2007.
Pressure-tuned colossal improvement of thermoelectric efficiency of PbTe
Sergey V. Ovsyannikov and Vladimir V. Shchennikov
The variations in thermoelectric (TE) efficiencies ae of lead chalcogenide compounds (p-PbTe, n-PbTe, p-Pb[sub 0.55]Te[sub 0.45], p-Pb[sub 1x]Sn[sub x]Te[sub 1y], p-PbSe, and p-PbS) at room temperature for the pressure P range of P~010 GPa are reported. A colossal (~100 times) pressure-tuned improv ... [Appl. Phys. Lett. 90, 122103 (2007)] published Mon Mar 19, 2007.
Assessment of accumulated fatigue damage in solid plates using nonlinear Lamb wave approach
Mingxi Deng and Junfeng Pei
The feasibility of using the nonlinear effect of primary Lamb wave propagation for assessing accumulated fatigue damage in solid plates is theoretically analyzed. After the aluminum sheets are subjected to tension-tension fatigue loading for different numbers of loading cycles, they are subjected to ... [Appl. Phys. Lett. 90, 121902 (2007)] published Mon Mar 19, 2007.
Observation of superluminal propagation at negative group velocity in C[sub 60] solution
Hao Wang, Yundong Zhang, Nan Wang, Wenlong Yan, He Tian et al.
The authors observed the superluminal propagation at negative group velocity in C[sub 60] toluene solution firstly. The theoretical analysis was made based on density matrix model of superluminal propagation. The simulation result was well consistent with experimental measurement. The largest time a ... [Appl. Phys. Lett. 90, 121107 (2007)] published Mon Mar 19, 2007.
High-symmetry ZnS hepta- and tetrapods composed of assembled ZnS nanowire arrays
G. Z. Shen, Y. Bando, J. Q. Hu, and D. Golberg
Sixfold symmetry heptapodlike and threefold symmetry tetrapodlike ZnS structures have been fabricated by thermal evaporation of a ZnS and SiO mixture source in N[sub 2] at 1300 degrees C. Both the heptapods and tetrapods have been formed by the self-assembly of ZnS nanowires with the preferred (00 ... [Appl. Phys. Lett. 90, 123101 (2007)] published Mon Mar 19, 2007.
High-power operation of diode edge-pumped, composite all-ceramic Yb:Y[sub 3]Al[sub 5]O[sub 12] microchip laser
Masaki Tsunekane and Takunori Taira
A solid-state laser material of composite all-ceramic Yb:Y[sub 3]Al[sub 5]O[sub 12] is applied as a source of a high-power, diode edge-pumped microchip laser. 520 W quasi-continuous-wave and 414 W continuous-wave (cw) output powers were obtained from the 3.7-mm-diameter, Yb doped ceramic core with ... [Appl. Phys. Lett. 90, 121101 (2007)] published Mon Mar 19, 2007.
Observation of temporal behavior of the emission frequency from an ultrashort, high-power, and compact millimeter-wave source
Takeshi Higashiguchi, Nobuo Ohata, Kun Li, and Noboru Yugami
The authors demonstrated observation of emission frequency chirping of millimeter-wave emission from a time-varying plasma produced by a nanosecond UV laser pulse. By using a heterodyne interferometer the time-resolved frequency of the emission from a dc to ac radiation converter source was observed ... [Appl. Phys. Lett. 90, 111503 (2007)] published Fri Mar 16, 2007.
Effects of (NH[sub 4])[sub 2]S[sub x] treatment on electrical properties of indium tin oxide/poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate)
Yow-Jon Lin, Hsing-Cheng Chang, and Bei-Yuan Liu
The effects of (NH[sub 4])[sub 2]S[sub x] treatment on the current-voltage characteristics and interfacial properties of the indium tin oxide (ITO)/poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) (PEDOT-PSS) samples have been investigated in this study. The authors found that (N ... [Appl. Phys. Lett. 90, 112112 (2007)] published Fri Mar 16, 2007.
Effect of enhanced C[sub 2] growth chemistry on nanodiamond film deposition
Kungen Teii and Tomohiro Ikeda
A route to high-purity nanocrystalline diamond films from C[sub 2] dimers and related mechanisms have been investigated by enhancing C[sub 2] growth chemistry in Ar-rich microwave plasmas. Efficient C[sub 2] production by direct dissociation from acetylene causes the micro- to nanocrystal transition ... [Appl. Phys. Lett. 90, 111504 (2007)] published Fri Mar 16, 2007.
Ultraviolet-enhanced device properties in pentacene-based thin-film transistors
Jeong-M. Choi, D. K. Hwang, Jung Min Hwang, Jae Hoon Kim, and Seongil Im
The authors report on the ultraviolet (UV)-enhanced device properties in pentacene-based thin-film transistors (TFTs). Pentacene TFTs showed a degraded mobility and lowered saturation current after illumination by a high energy UV with 254 nm wavelength. However, under 364 nm UV these devices surp ... [Appl. Phys. Lett. 90, 113515 (2007)] published Fri Mar 16, 2007.
Undoped high mobility two-dimensional hole-channel GaAs/Al[sub x]Ga[sub 1 - x]As heterostructure field-effect transistors with atomic-layer-deposited dielectric
T. M. Lu, D. R. Luhman, K. Lai, D. C. Tsui, L. N. Pfeiffer et al.
The authors have fabricated undoped p-channel GaAs/Al[sub x]Ga[sub 1x]As heterostructure field-effect transistors with nearly ideal drain current-voltage characteristics, using atomic-layer-deposited Al[sub 2]O[sub 3] as the dielectric, and measured their transport properties. At 0.3 K, the densiti ... [Appl. Phys. Lett. 90, 112113 (2007)] published Fri Mar 16, 2007.
Probing intrinsic polarization properties in bismuth-layered ferroelectric films
Takayuki Watanabe, Hiroshi Funakubo, Minoru Osada, Hiroshi Uchida, Isao Okada et al.
The authors report on an approach to establish intrinsic polarization properties in bismuth-layered ferroelectric films by piezoelectric coefficient and soft-mode spectroscopy, as well as by a direct polarizationelectric field hysteresis. In epitaxially grown (Bi[sub 4x]Nd[sub x])Ti[sub 3]O[sub 12] ... [Appl. Phys. Lett. 90, 112914 (2007)] published Fri Mar 16, 2007.
Electromigration-induced Kirkendall voids at the Cu/Cu[sub 3]Sn interface in flip-chip Cu/Sn/Cu joints
C. Y. Liu, J. T. Chen, Y. C. Chuang, Lin Ke, and S. J. Wang
Polarity void formation has been observed at the Cu[sub 3]Sn/Cu interfaces in current-stressed Cu/Sn/Cu flip-chip joints. Electromigration voids were observed at the Cu[sub 3]Sn/Cu anode interface, but no voids were found at the Cu[sub 3]Sn/Cu cathode interface. The backstress in the anode's Cu trac ... [Appl. Phys. Lett. 90, 112114 (2007)] published Fri Mar 16, 2007.
Criterion for predicting the glass-forming ability of alloys
S. Sharma, R. Vaidyanathan, and C. Suryanarayana
Mechanical alloying (MA) of blended elemental powder mixtures of Fe[sub 42]Zr[sub 10]X[sub 28]B[sub 20] (X=Al, Co, Ge, Mn, Ni, and Sn) was carried out to determine their glass-forming ability (GFA) (as determined by the time required to form the amorphous phase). During milling, amorphization was ac ... [Appl. Phys. Lett. 90, 111915 (2007)] published Fri Mar 16, 2007.
Evidence of enhanced phonon-energy coupling in SiO[sub 2]/Si
Pangleen Ong and Zhi Chen
The authors designed special pn junctions to examine the recently discovered phonon-energy-coupling enhancement effect. They found that the breakdown voltage of the silicon substrate is increased by 0.3 V after rapid thermal process (RTP), whereas it remains the same for diodes annealed in furnace ... [Appl. Phys. Lett. 90, 113516 (2007)] published Fri Mar 16, 2007.
Channel width effect on the spin-orbit interaction parameter in a two-dimensional electron gas
Jae Hyun Kwon, Hyun Cheol Koo, Joonyeon Chang, Suk-Hee Han, and Jonghwa Eom
The spin splitting energy obtained from the Shubnikovde Haas oscillation increases with decreasing channel width (w) of the InAs-based heterostructure. Since the surface charge concentration depends only weakly on w, the channel width dependence of the spin splitting energy is attributed to variatio ... [Appl. Phys. Lett. 90, 112505 (2007)] published Fri Mar 16, 2007.
Effects of rapid thermal annealing on the emission properties of highly uniform self-assembled InAs/GaAs quantum dots emitting at 1.3 mu m
Tao Yang, Jun Tatebayashi, Kanna Aoki, Masao Nishioka, and Yasuhiko Arakawa
The authors report the effects of rapid thermal annealing (RTA) on the emission properties of highly uniform self-assembled InAs quantum dots (QDs) emitting at 1.3 [mu]m grown on GaAs substrate by metal organic chemical vapor deposition. Postgrowth RTA experiments were performed under N[sub 2] flow ... [Appl. Phys. Lett. 90, 111912 (2007)] published Fri Mar 16, 2007.
Microcantilever mechanics in flowing viscous fluids
Anirban Jana, Arvind Raman, Babita Dhayal, Steven L. Tripp, and Ronald G. Reifenberger
Microcantilevers are often deployed in flowing fluids to measure local flow velocities or to detect rapidly the nanomechanical binding of trace quantities of target analytes. The authors investigate the flow-induced mechanics of microcantilevers by deriving a semianalytical theoretical model for the ... [Appl. Phys. Lett. 90, 114110 (2007)] published Fri Mar 16, 2007.
Electrical properties of germanium/metal-oxide gate stacks with atomic layer deposition grown hafnium-dioxide and plasma-synthesized interface layers
Takuya Sugawara, Yasuhiro Oshima, Raghavasimhan Sreenivasan, and Paul C. McIntyre
The electrical properties of metal-oxide-semiconductor (MOS) capacitors composed of atomic-layer-deposited (ALD) hafnium-dioxide (HfO[sub 2]) dielectrics and plasma-synthesized interface layers were investigated. MOS capacitor with oxynitride interface layer shows negative flatband voltage (V[sub fb ... [Appl. Phys. Lett. 90, 112912 (2007)] published Fri Mar 16, 2007.
InAs/AlSb quantum cascade lasers emitting below 3 mu m
J. Devenson, R. Teissier, O. Cathabard, and A. N. Baranov
Quantum cascade lasers emitting below 3 [mu]m are demonstrated. The lasers based on the InAs/AlSb material system emit at 2.952.97 [mu]m in pulsed mode with threshold current densities near 3 kA/cm[sup 2] at 84 K and operate up to room temperature. No degradation has been observed in laser perfo ... [Appl. Phys. Lett. 90, 111118 (2007)] published Fri Mar 16, 2007.
Multistable alignment states in nematic liquid crystal filled wells
C. Tsakonas, A. J. Davidson, C. V. Brown, and N. J. Mottram
Two distinct, stable alignment states have been observed for a nematic liquid crystal confined in a layer with thickness of 12 [mu]m and in square wells with sides of length between 20 and 80 [mu]m. The director lies in the plane of the layer and line defects occur in two corners of the squares. T ... [Appl. Phys. Lett. 90, 111913 (2007)] published Fri Mar 16, 2007.
Weak coupling interactions of colloidal lead sulphide nanocrystals with silicon photonic crystal nanocavities near 1.55 mu m at room temperature
Ranojoy Bose, Xiaodong Yang, Rohit Chatterjee, Jie Gao, and Chee Wei Wong
The authors observe the weak coupling of lead sulphide nanocrystals to localized defect modes of two-dimensional silicon nanocavities. Cavity resonances characterized with ensemble nanocrystals are verified with cold-cavity measurements using integrated waveguides. Polarization dependence of the cav ... [Appl. Phys. Lett. 90, 111117 (2007)] published Fri Mar 16, 2007.
Fluorine incorporation at HfO[sub 2]/SiO[sub 2] interfaces in high-k metal-oxide-semiconductor gate stacks: Local electronic structure
Jeong-Hee Ha, Kang-ill Seo, Paul C. McIntyre, Krishna C. Sarawat, and Kyeongjae Cho
Effects of fluorine incorporation on the electrical properties of HfO[sub 2]/SiO[sub 2] dielectric stacks are investigated through both ab initio simulations and electrical measurements. The results show that F ions are able to remove midgap states resulting from undercoordinated Hf ions at the HfO[ ... [Appl. Phys. Lett. 90, 112911 (2007)] published Fri Mar 16, 2007.
Ferroelectric all-polymer hollow Bragg fibers for terahertz guidance
Maksim Skorobogatiy and Alexandre Dupuis
Design of hollow all-polymer Bragg fibers using periodic multilayers of ferroelectric polyvinylidene fluoride (PVDF) polymer and a low loss polycarbonate (PC) polymer is demonstrated. Efficient band gap guiding is predicted near the transverse optical frequency of a PVDF material in the terahertz re ... [Appl. Phys. Lett. 90, 113514 (2007)] published Fri Mar 16, 2007.
Spin-transfer-induced magnetization switching in tunnel junctions with nanocurrent channels
Yisong Zhang, Zongzhi Zhang, Yaowen Liu, B. Ma, and Q. Y. Jin
Spin-transfer-induced magnetization switching processes are evidenced by the snapshots of magnetic configurations for junctions containing nanocurrent channels (NCCs). The switching behaviors are found to be closely related to the NCC size and its actual location. Both the switching time t and criti ... [Appl. Phys. Lett. 90, 112504 (2007)] published Fri Mar 16, 2007.
Low-threshold-switch phototransistor based on Kirk effect and float-zone silicon
D. B. Zhou, D. J. Han, C. M. Sun, R. Yang, and K. Liang
Based on the Kirk effect, a n[sup +]pn[sup ]n[sup +] phototransistor with low optical threshold switching on high purity float-zone silicon was demonstrated. Under a collector-emitter voltage range from 3 to 15 V, the phototransistor can turn on from a lower current state (range from 0.29 to 0. ... [Appl. Phys. Lett. 90, 113513 (2007)] published Fri Mar 16, 2007.
Visible submicron microdisk lasers
Zhaoyu Zhang, Lan Yang, Victor Liu, Ting Hong, Kerry Vahala et al.
The authors describe the performance of submicron microdisk lasers fabricated within InGaP/InGaAlP quantum well material working at room temperature. The smallest lasers, with diameters of approximately 600 nm, feature ultrasmall mode volumes and exhibit single mode operation at low threshold power ... [Appl. Phys. Lett. 90, 111119 (2007)] published Fri Mar 16, 2007.
Fabrication and material properties of submicrometer SrTiO[sub 3] films exfoliated using crystal ion slicing
Ryan M. Roth, Djordje Djukic, Yoo Seung Lee, Richard M. Osgood, Jr., Penelope A. Lewis et al.
The crystal quality of submicrometer-thick SrTiO[sub 3] films that are formed by exfoliation from bulk crystals using deep implantation with H-ion beams is investigated. Nuclear reaction analysis and Rutherford backscattering/channeling are used to measure the implantation depth, crystal-lattice dis ... [Appl. Phys. Lett. 90, 112913 (2007)] published Fri Mar 16, 2007.
Strain field in silicon on insulator lines using high resolution x-ray diffraction
M. Gailhanou, A. Loubens, J.-S. Micha, B. Charlet, A. A. Minkevich et al.
Symmetric and asymmetric reciprocal space maps (RSMs) of silicon on insulator (SOI) lines are obtained using high resolution x-ray diffraction. RSMs calculated from the displacement field simulated using finite element calculations show a good agreement with the experimental RSMs. These calculations ... [Appl. Phys. Lett. 90, 111914 (2007)] published Fri Mar 16, 2007.
FeCoSiN film with ordered FeCo nanoparticles embedded in a Si-rich matrix
Yan Liu, C. Y. Tan, Z. W. Liu, and C. K. Ong
FeCoSiN film consisting of ordered arrays of FeCo nanoparticles embedded in a Si-rich matrix was fabricated on silicon substrate by reactive rf magnetron sputtering. These nanoparticles have a face-centered cubic structure and a mean diameter of ~7 nm. The FeCoSiN film has a very high resistivity o ... [Appl. Phys. Lett. 90, 112506 (2007)] published Fri Mar 16, 2007.
Ultraviolet light-emitting diodes with self-assembled InGaN quantum dots
Il-Kyu Park, Min-Ki Kwon, Seong-Bum Seo, Ja-Yeon Kim, Jae-Hong Lim et al.
A photoluminescence study showed that the self-assembled InGaN quantum dots (QDs) provide strongly localized recombination sites for carriers and that the piezoelectric field-induced quantum-confined Stark effect (QCSE) is small because the height of QDs is too small to separate the wave functions o ... [Appl. Phys. Lett. 90, 111116 (2007)] published Fri Mar 16, 2007.
Radio-frequency dielectric-barrier glow discharges in atmospheric argon
J. J. Shi and M. G. Kong
In this letter, an experimental investigation is presented to characterize the properties and benefits of radio-frequency (rf) dielectric-barrier discharges (DBDs) in atmospheric argon. Compared to rf atmospheric glow discharges generated with bare electrodes, atmospheric argon rf DBDs are shown to ... [Appl. Phys. Lett. 90, 111502 (2007)] published Thu Mar 15, 2007.
Synthesis and band gap of ZnO particles with hexagonal bilayer structure
Jianhui Zhang, Huaiyong Liu, Zhenlin Wang, and Naiben Ming
The unique water/PVP (polyvinylpyrrolidone)/n-pentanol interface has been developed to prepare the ZnO particles with hexagonal bilayer structure. By modifying the interface through varying the amount of PVP and water, one can readily tune the particle size and change the particle shape from hexagon ... [Appl. Phys. Lett. 90, 113117 (2007)] published Thu Mar 15, 2007.
Electron density dependence of in-plane spin relaxation anisotropy in GaAs/AlGaAs two-dimensional electron gas
Baoli Liu, Hongming Zhao, Jia Wang, Linsheng Liu, Wenxin Wang et al.
The authors investigated the spin dynamics of two-dimensional electrons in (001) GaAs/AlGaAs heterostructure using the time-resolved Kerr rotation technique under a transverse magnetic field. The in-plane spin lifetime is found to be anisotropic below 150 K due to the interference of Rashba [J. Phy ... [Appl. Phys. Lett. 90, 112111 (2007)] published Thu Mar 15, 2007.
Comment on ``Photoluminescence study of Sb-doped p-type ZnO films by molecular-beam epitaxy'' [Appl. Phys. Lett. [bold 87], 252102 (2005)]
Y. J. Zeng and Z. Z. Ye
... [Appl. Phys. Lett. 90, 116102 (2007)] published Thu Mar 15, 2007.
Electrochemical grafting of octyltrichlorosilane monolayer on Si
S. P. Koiry, D. K. Aswal, Vibha Saxena, N. Padma, A. K. Chauhan et al.
The octyltrichlorosilane (OTS) monolayer on hydrated Si (111) surfaces has been grafted by cyclic voltammetry (CV) using tetrabutylammonium perchlorate in dry methanol as supporting electrolyte. The percentage of OTS coverage, calculated from the current value at 1 V, after 30 CV scans was found to ... [Appl. Phys. Lett. 90, 113118 (2007)] published Thu Mar 15, 2007.
Design of a crystalline undulator based on patterning by tensile Si[sub 3]N[sub 4] strips on a Si crystal
V. Guidi, L. Lanzoni, A. Mazzolari, G. Martinelli, and A. Tralli
A crystalline undulator consists of a crystal with a periodic deformation in which channeled particles undergo oscillations and emit coherent undulator radiation. Patterning by an alternate series of tensile Si[sub 3]N[sub 4] strips on a Si crystal is shown to be a tractable method to construct a cr ... [Appl. Phys. Lett. 90, 114107 (2007)] published Thu Mar 15, 2007.
Shape and composition of buried PbSe quantum dots determined by scanning tunneling microscopy
G. Springholz, L. Abtin, and V. Holy
Capping of self-assembled semiconductor quantum dots usually alters their shape and composition due to alloying with the matrix material. To determine the structure of capped dots, a method is developed based on the analysis of surface displacements induced by buried dots measured by scanning tunnel ... [Appl. Phys. Lett. 90, 113119 (2007)] published Thu Mar 15, 2007.
Dependence of breakdown field on dielectric (interelectrode) thickness in base-metal electroded multilayer capacitors Response to ``Comment on `Photoluminescence study of Sb-doped p-type ZnO films by molecular-beam epitaxy''' [Appl. Phys. Lett. [bold 90], 116102 (2007)] Experimental demonstration of bending and splitting of self-collimated beams in two-dimensional photonic crystals Exchange bias effect and enhanced magnetoresistance in La[sub 0.67]Sr[sub 0.33]MnO[sub 3]/SrTiO[sub 3] superlattices Publisher's Note: ``Efficient third harmonic generation of microjoule picosecond pulses at 355 nm in BiB[sub 3]O[sub 6][Appl. Phys. Lett. [bold 89], 173124 (2006)] Analytical description of the motion of an acoustic-driven atomic force microscope cantilever in liquid Organic light-emitting diodes with photonic crystals on glass substrate fabricated by nanoimprint lithography Magneto-optical and magnetotransport properties of heavily Mn-doped GaMnAs Electron capture acceleration channel in a slit laser beam Polarization transfer from photon to electron spin in g factor engineered quantum wells Scaling of interface displacement in a microfluidic comparator Nanoholes fabricated by self-assembled gallium nanodrill on GaAs(100) Prototype dispenser photocathode: Demonstration and comparison to theory Refractive femtosecond laser beam shaping for two-photon polymerization Wafer-level filling of microfabricated atomic vapor cells based on thin-film deposition and photolysis of cesium azide High pressure bulk synthesis and characterization of the predicted multiferroic Bi(Fe[sub 1/2]Cr[sub 1/2])O[sub 3] Red and near infrared polarized light emissions from polyfluorene copolymer based light emitting diodes (In,Ga)N/GaN microcavities with double dielectric mirrors fabricated by selective removal of an (Al,In)N sacrificial layer Excimer laser annealing of silicon nanowires Doping dependence of thermopower and thermoelectricity in strongly correlated materials Determination of Young's modulus of individual electrospun nanofibers by microcantilever vibration method Bamboolike carbon nitride nanotubes (C[sub 9]N[sub 5]H[sub 3]): Atomic-scale construction, synthesis and lithium battery applications Formation of stacked Ni silicide nanocrystals for nonvolatile memory application Heteroepitaxially enhanced magnetic anisotropy in BaTiO[sub 3]--CoFe[sub 2]O[sub 4] nanostructures Photoluminescence from low temperature grown InAs/GaAs quantum dots Assembly of one-dimensional nanorods into Bi[sub 2]S[sub 3] films with enhanced thermoelectric transport properties Influence of crystallite size on the thermal conductivity in BaTiO[sub 3] nanoceramics High quality Fe[sub 3 - delta]O[sub 4]/InAs hybrid structure for electrical spin injection Channel cracks in a hermetic coating consisting of organic and inorganic layers Automatic navigation of an untethered device in the artery of a living animal using a conventional clinical magnetic resonance imaging system Nanoscale quantitative stress mapping with atomic force microscopy GaSb homojunctions for far-infrared (terahertz) detection Size-dependent planar colloidal crystals guided by alternating electric field Integrated waveguide with a microfluidic channel in spiral geometry for spectroscopic applications Dynamic hysteresis and scaling behavior of hard lead zirconate titanate bulk ceramics Structure stability, fracture, and tuning mechanism of CdSe nanobelts Alpha-particle irradiation-induced defects in n-type germanium Regular arrangement of nanoparticles from the gas phase on bacterial surface-protein layers Effects of morphology and optical contrast in organic distributed feedback lasers Monodisperse spherical mesoporous Eu-doped TiO[sub 2] phosphor particles and the luminescence properties On the nature of the carriers in ferromagnetic FeSe Characteristics of (Pb,Sr)TiO[sub 3]/ZrO[sub 2] structures on Si and SiON/Si substrates Practicable enhancement of spontaneous emission using surface plasmons Propagation of Lamb waves in one-dimensional quasiperiodic composite thin plates: A split of phonon band gap Temperature scaling of dynamic hysteresis in soft lead zirconate titanate bulk ceramic Spin-orbit interaction enhanced polaron effect in two-dimensional semiconductors Changes in microbubble dynamics near a boundary revealed by combined optical micromanipulation and high-speed imaging Synthesis and optical properties of InN nanowires and nanotubes In situ electrical conductivity measurement of high-pressure molten (Mg[sub 0.875],Fe[sub 0.125])[sub 2]SiO[sub 4] Origin of the drain current bistability in polymer ferroelectric field-effect transistors Quasimonochromatic emission spectra in the near field by polar semiconductor thermal sources Relaxor behavior in the solid solution between dielectric Ba(Mg[sub 1/3]Nb[sub 2/3])O[sub 3] and ferroelectric PbTiO[sub 3] Publisher's Note: ``Nucleation and growth of NiSi from Ni[sub 2]Si transrotational domains'' [Appl. Phys. Lett. 90, 053507 (2007)] Formation of single crystalline ZnO nanotubes without catalysts and templates Electrical properties of oxide heteroepitaxial p-n junctions: La[sub 1 - x]Sr[sub x]FeO[sub 3]/SrTi[sub 0.99]Nb[sub 0.01]O[sub 3] Erratum: ``Low-field inverse magnetocaloric effect in Ni[sub 50 - x]Mn[sub 39 + x]Sn[sub 11] Heusler alloys'' [Appl. Phys. Lett. [bold 90], 042507 (2007)] Study of copper diffusion through a ruthenium thin film by photoemission electron microscopy Mechanism of leakage current reduction of tantalum oxide capacitors by titanium doping Image enhanced polymer-based multimode interference coupler covering C and L bands using deeply etched air trenches Thickness dependent ion conductivity of lithium borate network glasses Three-image diffraction enhanced imaging algorithm to extract absorption, refraction, and ultrasmall-angle scattering Enhanced mass sensitivity of stress-free, silicon nanowire-grown microcantilever sensors Prospects for electron imaging with ultrafast time resolution Simultaneous filling of InAs quantum dot states from the GaAs barrier under nonresonant excitation Influence of interface layer composition on the electrical properties of epitaxial Gd[sub 2]O[sub 3] thin films for high-K application Correlation between the dynamics of polar nanoregions and temperature evolution of central peaks in Pb[(Zn[sub 1/3]Nb[sub 2/3])[sub 0.91]Ti[sub 0.09]]O[sub 3] ferroelectric relaxors Negative magnetoresistance in fractal Pb thin films on Si(111)
Alexander D. Milliken, Andrew J. Bell, and James F. Scott
The authors have empirically determined the dependence of breakdown field E[sub B] versus dielectric thickness d (electrode separation) for a large number (4100) of BaTiO[sub 3]-based multilayer capacitors with Ni base-metal electrodes. The data averaged over lateral area show for 6
F. X. Xiu and J. L. Liu
... [Appl. Phys. Lett. 90, 116103 (2007)] published Thu Mar 15, 2007.
Myeong-Woo Kim, Sun-Goo Lee, Teun-Teun Kim, Jae-Eun Kim, Hae Yong Park et al.
The authors have experimentally demonstrated the bending and splitting phenomena of self-collimated microwave beams in a two-dimensional square lattice photonic crystal composed of alumina rods. The bending and splitting were achieved by introducing a line defect in the photonic crystal. The power r ... [Appl. Phys. Lett. 90, 113121 (2007)] published Thu Mar 15, 2007.
S. J. Zhu, J. Yuan, B. Y. Zhu, F. C. Zhang, B. Xu et al.
The magnetization and electrical transport in the superlattices consisting of ferromagnetic La[sub 0.67]Sr[sub 0.33]MnO[sub 3] and nonmagnetic insulating SrTiO[sub 3] layers have been investigated. A significant displacement of the hysteresis loop along the field axis is observed when the sample is ... [Appl. Phys. Lett. 90, 112502 (2007)] published Thu Mar 15, 2007.
M. Ghotbi, Z. Sun, A. Majchrowski, E. Michalski, I. V. Kityk et al.
... [Appl. Phys. Lett. 90, 119903 (2007)] published Thu Mar 15, 2007.
Cedric Jai, Touria Cohen-Bouhacina, and Abdelhamid Maali
In this letter the authors present an analytical description that enables determining the motion of an acoustic-driven atomic force microscope cantilever in liquid. The authors show that for low quality factors the effective driving force that acts on the deflection motion depends on the damping. Th ... [Appl. Phys. Lett. 90, 113512 (2007)] published Thu Mar 15, 2007.
Kuniaki Ishihara, Masayuki Fujita, Ippei Matsubara, Takashi Asano, Susumu Noda et al.
The authors have fabricated organic light-emitting diodes (OLEDs) having two-dimensional photonic crystals (PC) as light extraction elements by employing nanoimprint lithography technique. PCs were imprinted on the glass substrate and OLED layers were formed on the imprinted side of the glass substr ... [Appl. Phys. Lett. 90, 111114 (2007)] published Thu Mar 15, 2007.
Shinobu Ohya, Kenichi Ohno, and Masaaki Tanaka
The authors have studied the magneto-optical and magnetotrasnport properties of Ga[sub 1x]Mn[sub x]As thin films with high Mn concentrations (x=12.2%21.3%) grown by molecular-beam epitaxy. These heavily Mn-doped GaMnAs films were formed by decreasing the growth temperature to as low as 150190 degr ... [Appl. Phys. Lett. 90, 112503 (2007)] published Thu Mar 15, 2007.
P. X. Wang, W. Scheid, and Y. K. Ho
Using numerical simulations, the authors find that the electrons can be captured and accelerated to high energies (GeV) in a slit laser beam with an intensity of Ilambda[sup 2]~10[sup 20] W/cm[sup 2] [mu]m[sup 2], where lambda is the laser wavelength in units of [mu]m. The range of the optimum inc ... [Appl. Phys. Lett. 90, 111113 (2007)] published Thu Mar 15, 2007.
H. Kosaka, Y. Mitsumori, Y. Rikitake, and H. Imamura
The authors demonstrate polarization transfer from a photon to an electron spin intermediated by a light-hole exciton in a GaAs/AlGaAs quantum well, which has an engineered electron g factor of less than 0.01 for an in-plane magnetic field. Negative spin polarization was clearly observed at the sele ... [Appl. Phys. Lett. 90, 113511 (2007)] published Thu Mar 15, 2007.
S. A. Vanapalli, D. van den Ende, M. H. G. Duits, and F. Mugele
The authors quantify both experimentally and theoretically the scaling behavior between interface displacement and excess pressure drop in a microfluidic comparator. Unlike previous studies, the authors measure the interface displacement in the outlet channel of the comparator that yields a unique p ... [Appl. Phys. Lett. 90, 114109 (2007)] published Thu Mar 15, 2007.
Zh. M. Wang, B. L. Liang, K. A. Sablon, and G. J. Salamo
Self-assembled nanodrill technology based on droplet epitaxy growth was developed to obtain nanoholes on a GaAs(100) surface. In this technology, the gallium droplets act like electrochemical drills etching away the GaAs substrate beneath to give rise to nanoholes more than 10 nm deep. The driving ... [Appl. Phys. Lett. 90, 113120 (2007)] published Thu Mar 15, 2007.
N. A. Moody, K. L. Jensen, D. W. Feldman, P. G. O'Shea, and E. J. Montgomery
A method to significantly extend the operational lifetime of alkali-based photocathodes by diffusing cesium to the surface at moderate temperature is presented and shown to restore the quantum efficiency (QE) of cesiated tungsten. Experimental measurements of QE as a function of surface cesium cover ... [Appl. Phys. Lett. 90, 114108 (2007)] published Thu Mar 15, 2007.
R. J. Winfield, B. Bhuian, S. O'Brien, and G. M. Crean
Three dimensional microstructure fabrication by two-photon polymerization is an established technique that normally uses single beam serial writing. Recently the use of a micro-optical element, to give multipoint beam delivery, was reported to give a degree of parallel processing. The authors descri ... [Appl. Phys. Lett. 90, 111115 (2007)] published Thu Mar 15, 2007.
Li-Anne Liew, John Moreland, and Vladislav Gerginov
The thin-film deposition and photodecomposition of cesium azide are demonstrated and used to fill arrays of miniaturized atomic resonance cells with cesium and nitrogen buffer gas for chip-scale atomic-based instruments. Arrays of silicon cells are batch fabricated on wafers into which cesium azide ... [Appl. Phys. Lett. 90, 114106 (2007)] published Thu Mar 15, 2007.
Matthew R. Suchomel, Chris I. Thomas, Mathieu Allix, Matthew J. Rosseinsky, Andrew M. Fogg et al.
Bi(Fe[sub 1/2]Cr[sub 1/2])O[sub 3], a recently proposed candidate multiferroic perovskite, is prepared in a bulk form by high pressure solid-state synthesis. The material is isostructural with polar BiFeO[sub 3] but is paramagnetic at room temperature due to disorder of the Fe[sup 3+] and Cr[sup 3+] ... [Appl. Phys. Lett. 90, 112909 (2007)] published Thu Mar 15, 2007.
Abay Gadisa, Erik Perzon, Mats R. Andersson, and Olle Inganas
The authors report polarized red, electroluminescence peak at 705 nm and near infrared, electroluminescence peak at 950 nm, light emission from light emitting diodes based on two polyfluorene copolymers. The copolymers are synthesized from a fluorene monomer combined with donor-acceptor-donor como ... [Appl. Phys. Lett. 90, 113510 (2007)] published Thu Mar 15, 2007.
F. Rizzi, P. R. Edwards, K. Bejtka, F. Semond, X. N. Kang et al.
Comparable microcavities with 3lambda/2 (~240 nm) active regions containing distributed (In,Ga)N quantum wells, grown on GaN substrates and bounded by two dielectric mirrors, have been fabricated by two different routes: one using laser lift-off to process structures grown on GaN-on-sapphire templa ... [Appl. Phys. Lett. 90, 111112 (2007)] published Thu Mar 15, 2007.
Nipun Misra, Li Xu, Yaoling Pan, Nathan Cheung, and Costas P. Grigoropoulos
Nanowires can potentially be used with low-cost flexible plastic substrates for applications such as large-area displays and sensor arrays. However, high temperature processing steps such as thermal annealing that are incompatible with plastic substrates are still a major hindrance. Laser annealing ... [Appl. Phys. Lett. 90, 111111 (2007)] published Wed Mar 14, 2007.
Subroto Mukerjee and Joel E. Moore
The search for efficient semiconductor thermoelectrics has been greatly aided by theoretical modeling of electron and phonon transports in bulk materials and nanocomposites. Recent experiments have studied thermoelectric transport in thermoelectrics that are strongly correlated and derived by doping ... [Appl. Phys. Lett. 90, 112107 (2007)] published Wed Mar 14, 2007.
Philip A. Yuya, Yongkui Wen, Joseph A. Turner, Yuris A. Dzenis, and Zheng Li
The authors report a technique for measuring Young's modulus of a single electrospun nanofiber using the vibrations of two microcantilevers coupled with the nanofiber. The modulus is calculated from the resonant frequency shift resulting from the nanofiber. Polyacrylonitrile nanofibers (200 nm diam ... [Appl. Phys. Lett. 90, 111909 (2007)] published Wed Mar 14, 2007.
Changzheng Wu, Xi Zhu, Chengle Wang, Hua Sheng, Jinlong Yang et al.
The authors constructed the finite cluster model of bamboolike carbon nitride nanotubes taking the C[sub 9]N[sub 5]H[sub 3] as an example. As desired, the C[sub 9]N[sub 5]H[sub 3] bamboolike nanotubes were prepared in a facile solvent-free system. Both x-ray photoelectron microscopy and elemental an ... [Appl. Phys. Lett. 90, 113116 (2007)] published Wed Mar 14, 2007.
Wei-Ren Chen, Ting-Chang Chang, Po-Tsun Liu, Po-Sun Lin, Chun-Hao Tu et al.
The formation of stacked Ni silicide nanocrystals by using a comixed target is proposed in this letter. High resolution transmission electron microscope analysis clearly shows the stacked nanocrystals embedded in the silicon oxide. The memory window enough to define 1 and 0 states is obviously obser ... [Appl. Phys. Lett. 90, 112108 (2007)] published Wed Mar 14, 2007.
Haimei Zheng, Jens Kreisel, Ying-Hao Chu, R. Ramesh, and Lourdes Salamanca-Riba
The authors have studied the magnetic properties of BaTiO[sub 3]CoFe[sub 2]O[sub 4] nanostructures, which were prepared using pulsed laser deposition. Such nanostructures show a large uniaxial magnetic anisotropy with an easy axis along the pillar long direction. As the growth temperature decreases, ... [Appl. Phys. Lett. 90, 113113 (2007)] published Wed Mar 14, 2007.
D. Sreenivasan, J. E. M. Haverkort, T. J. Eijkemans, and R. Notzel
The authors investigated a set of self-assembled InAs/GaAs quantum dots (QDs) formed by molecular beam epitaxy at low temperature (LT, 250 degrees C) and postgrowth annealing. A QD photoluminescence (PL) peak around 1.01 eV was observed. The PL efficiency quickly quenches between 6 and 40 K due ... [Appl. Phys. Lett. 90, 112109 (2007)] published Wed Mar 14, 2007.
Sheng-Cong Liufu, Li-Dong Chen, Qin Yao, and Chun-Fen Wang
Bismuth sulfide thin films have been assembled by cross-linkage nanorods on surface-functionalized Si substrate with self-assembled monolayers. Results of transmission electron microscopy and electron diffraction revealed that highly crystalline Bi[sub 2]S[sub 3] nanorods grow along c-axis direction ... [Appl. Phys. Lett. 90, 112106 (2007)] published Wed Mar 14, 2007.
A. Jezowski, J. Mucha, R. Pazik, and W. Strek
The grain size effect on the thermal conductivity in BaTiO[sub 3] nanoceramics was investigated. The nanoceramics were produced by the low temperature high pressure technique. The averaged sizes of grain varied from 30 to 100 nm. It was found that the thermal conductivity of BaTiO[sub 3] nanocera ... [Appl. Phys. Lett. 90, 114104 (2007)] published Wed Mar 14, 2007.
Marhoun Ferhat and Kanji Yoh
Single crystalline Fe[sub 3delta]O[sub 4] (0<=delta<=0.33) films have been epitaxially grown on InAs (001) substrates by molecular beam epitaxy using O[sub 2] as source of active oxygen. Under optimum growth conditions, in situ real time reflection high-energy electron diffraction patterns, along wi ... [Appl. Phys. Lett. 90, 112501 (2007)] published Wed Mar 14, 2007.
Nicolas Cordero, Juil Yoon, and Zhigang Suo
Flexible electronic devices often require hermetic coatings that can withstand applied strains. This letter calculates the critical strains for various configurations of channel cracks in a coating consisting of organic and inorganic layers. The authors show that the coating can sustain the largest ... [Appl. Phys. Lett. 90, 111910 (2007)] published Wed Mar 14, 2007.
Sylvain Martel, Jean-Baptiste Mathieu, Ouajdi Felfoul, Arnaud Chanu, Eric Aboussouan et al.
The feasibility for in vivo navigation of untethered devices or robots is demonstrated with the control and tracking of a 1.5 mm diameter ferromagnetic bead in the carotid artery of a living swine using a clinical magnetic resonance imaging (MRI) platform. Navigation is achieved by inducing displac ... [Appl. Phys. Lett. 90, 114105 (2007)] published Wed Mar 14, 2007.
Kerem Unal and H. Kumar Wickramasinghe
A nanometer scale noninvasive method for quantitatively mapping tensile strain in metals or semiconductors is demonstrated. The technique is based on the Kelvin probe force microscopy detection of changes in the electronic work function of a material resulting from the tensile strain. Measurements a ... [Appl. Phys. Lett. 90, 113111 (2007)] published Wed Mar 14, 2007.
P. V. V. Jayaweera, S. G. Matsik, A. G. U. Perera, Y. Paltiel, Ariel Sher et al.
A GaSb based homojunction interfacial work function internal photoemission far-infrared (>30 [mu]m) detector is presented. Metal-organic vapor phase epitaxy grown p-GaSb/GaSb samples show 9.7 A/W peak responsivity and a peak detectivity of 5.7 x 10[sup 11] Jones with effective quantum efficiency o ... [Appl. Phys. Lett. 90, 111109 (2007)] published Wed Mar 14, 2007.
Ke-Qin Zhang and Xiang Y. Liu
The authors demonstrate that two-dimensional crystals can be assembled from suspensions of colloidal spheres subjected to an alternating electric field on the surface of electrodes. The order parameters of monolayer colloidal crystals, which are extracted from the translational correlation function ... [Appl. Phys. Lett. 90, 111911 (2007)] published Wed Mar 14, 2007.
Linan Jiang and Stanley Pau
The authors fabricated and tested a compact optical sensor with an integrated waveguide and a microchannel in spiral geometry. The multimode waveguide, consisting of an SU-8 core of 40 [mu]m thick and 50 [mu]m wide and a fluid cladding layer of 60 [mu]m thick, realizes a light-fluid interaction l ... [Appl. Phys. Lett. 90, 111108 (2007)] published Wed Mar 14, 2007.
R. Yimnirun, R. Wongmaneerung, S. Wongsaenmai, A. Ngamjarurojana, S. Ananta et al.
The scaling relation of ferroelectric hysteresis area against frequency f and field amplitude E[sub 0] for the saturated loops of the hard lead zirconate titanate bulk ceramic takes the form of [proportional]f[sup 0.28]E[sub 0][sup 0.89], while that for the minor loops takes the form of [p ... [Appl. Phys. Lett. 90, 112908 (2007)] published Wed Mar 14, 2007.
Zhongwu Wang, Ken Finkelstein, Chris Ma, and Zhong Lin Wang
High pressure synchrotron x-ray diffraction studies have been conducted to explore the structural stability, phase transformation, and resulting mechanisms of CdSe nanobelts. 25-nm-thick wurtzite CdSe nanobelts transform to a rocksalt structure with in situ fracture at 4.0 GPa; this is greater than ... [Appl. Phys. Lett. 90, 113115 (2007)] published Wed Mar 14, 2007.
Vl. Kolkovsky, M. Christian Petersen, and A. Nylandsted Larsen
Deep level transient spectroscopy and high-resolution Laplace deep level transient spectroscopy were used to investigate alpha-particle irradiation-induced defects in n-type Ge. It is proposed that there is no electrically active divacancy level in the upper half of the band gap. A dominant peak has ... [Appl. Phys. Lett. 90, 112110 (2007)] published Wed Mar 14, 2007.
Ute Queitsch, Elias Mohn, Franziska Schaffel, Ludwig Schultz, Bernd Rellinghaus et al.
FePt nanoparticles from the gas phase are deposited onto the two-dimensional crystalline surface layer protein from the bacterium Bacillus sphaericus NCTC 9602. The potential of this protein layer to facilitate the ordered spatial arrangement of the otherwise statistically distributed nanoparticles ... [Appl. Phys. Lett. 90, 113114 (2007)] published Wed Mar 14, 2007.
M. Salerno, G. Gigli, M. Zavelani-Rossi, S. Perissinotto, and G. Lanzani
Optically pumped organic distributed feedback lasers, based on the same cavity geometry and polymeric active material, but patterned with different methods, are compared. In one case, the pattern is transferred into the polymer by spin coating the latter on top of a silica master. In the other case, ... [Appl. Phys. Lett. 90, 111110 (2007)] published Wed Mar 14, 2007.
Jianbo Yin, Liqin Xiang, and Xiaopeng Zhao
Monodisperse spherical and mesoporous Eu-doped TiO[sub 2] phosphor particles were prepared by nonionic surfactant-assisted soft-chemistry method. It is shown that the phosphor particles possess submicron diameter of about 250 nm and narrow size distribution. Under ultraviolet irradiation the partic ... [Appl. Phys. Lett. 90, 113112 (2007)] published Wed Mar 14, 2007.
X. J. Wu, D. Z. Shen, Z. Z. Zhang, J. Y. Zhang, K. W. Liu et al.
The optical and electrical properties of FeSe thin films are studied by both optical absorption and Hall measurements, which suggest that ferromagnetic FeSe is a metal instead of a semiconductor. No absorption gap is observed in the whole spectrum range from far infrared to ultraviolet. Temperature ... [Appl. Phys. Lett. 90, 112105 (2007)] published Wed Mar 14, 2007.
Hung-Yao Chen, Jenn-Ming Wu, Hsin-Erh Huang, and Hui-Yun Bor
The ferroelectric (Pb,Sr)TiO[sub 3] (PST) thin film with ZrO[sub 2] insulating buffer on Si and SiON(3 nm)/Si substrates was fabricated by rf magnetron sputtering. ZrO[sub 2] demonstrates excellent insulating properties on either Si or SiON/Si substrates. The metal-ferroelectric-insulator-semicondu ... [Appl. Phys. Lett. 90, 112907 (2007)] published Wed Mar 14, 2007.
Greg Sun, Jacob B. Khurgin, and Richard A. Soref
The authors develop a rigorous theory of the enhancement of spontaneous emission from a light emitting device via coupling the radiant energy in and out of surface plasmon polaritons (SPPs) on the metal-dielectric interface. Using the GaN/Ag system as an example, the authors show that using SPP pays ... [Appl. Phys. Lett. 90, 111107 (2007)] published Wed Mar 14, 2007.
Jian Gao, Jian-Chun Cheng, and Baowen Li
The authors study numerically the propagation of Lamb waves in one-dimensional quasiperiodic composite thin plates made of tungsten (B) and silicon resin (A) arranged according to a Fibonacci sequence. It is found that the band-gap structures of Lamb waves are very different from those of bulk waves ... [Appl. Phys. Lett. 90, 111908 (2007)] published Tue Mar 13, 2007.
R. Yimnirun, R. Wongmaneerung, S. Wongsaenmai, A. Ngamjarurojana, S. Ananta et al.
The temperature scaling of the dynamic hysteresis was investigated in soft ferroelectric bulk ceramic. The power-law temperature scaling relations were obtained for hystersis area and remnant polarization P[sub r], while the coercivity E[sub C] was found to scale linearly with temperature T. The ... [Appl. Phys. Lett. 90, 112906 (2007)] published Tue Mar 13, 2007.
Zhou Li, Zhongshui Ma, A. R. Wright, and Chao Zhang
It is shown that in two-dimensional semiconductors, the electron-phonon interaction and polaron mass correction are both significantly enhanced by the Rashba spin-orbit coupling. The mass correction is positive for the upper Rashba branch and negative for the lower Rashba branch. Both Rashba branche ... [Appl. Phys. Lett. 90, 112103 (2007)] published Tue Mar 13, 2007.
V. Garbin, D. Cojoc, E. Ferrari, E. Di Fabrizio, M. L. J. Overvelde et al.
The authors report optical observations of the change in the dynamics of one and the same ultrasound contrast agent microbubble due to the influence of interfaces and neighboring bubbles. The bubble is excited by a 2.25 MHz ultrasound burst and its oscillations are recorded with an ultrahigh-speed ... [Appl. Phys. Lett. 90, 114103 (2007)] published Tue Mar 13, 2007.
H. Y. Xu, Z. Liu, X. T. Zhang, and S. K. Hark
InN nanowires and faceted hexagonal InN nanotubes are synthesized by catalyst-free chemical vapor deposition at different temperatures. Both have the single crystalline wurtzite structure and grow along the c axis. Different growth dynamics are suggested for the difference in morphology. Observation ... [Appl. Phys. Lett. 90, 113105 (2007)] published Tue Mar 13, 2007.
Ming Li, Chunxiao Gao, Yanzhang Ma, Duojun Wang, Yanchun Li et al.
In situ resistance measurement of mantle mineral under high temperature and pressure has been considered an important method for studying the electrical properties and thermal states of Earth's interior. Here the authors report the results of the electrical conductivity of molten olivine [(Mg[sub 0. ... [Appl. Phys. Lett. 90, 113507 (2007)] published Tue Mar 13, 2007.
R. C. G. Naber, J. Massolt, M. Spijkman, K. Asadi, P. W. M. Blom et al.
The authors present measurements that elucidate the mechanism behind the observed drain current bistability in ferroelectric field-effect transistors based on the ferroelectric polymer poly(vinylidene fluoride-trifluoroethylene) as the gate dielectric. Capacitance-voltage measurements on metal-insul ... [Appl. Phys. Lett. 90, 113509 (2007)] published Tue Mar 13, 2007.
V. N. Sokolov, B. D. Kong, K. W. Kim, and R. J. Trew
The near-field spectra of the electromagnetic field emitted from a planar surface are theoretically investigated for a number of polar semiconductor and dielectric materials that support surface phonon polaritons. All of the studied materials, InP, GaAs, GaN, SiC, and alpha-Al[sub 2]O[sub 3] (sapphi ... [Appl. Phys. Lett. 90, 113106 (2007)] published Tue Mar 13, 2007.
Xifa Long and Zuo-Guang Ye
Relaxor behavior has been found in the solid solution between complex perovskite Ba(Mg[sub 1/3]Nb[sub 2/3])O[sub 3] (BMN) and ferroelectric PbTiO[sub 3] (PT), 0.4BMN-0.6PT, prepared by solid state reactions. A strong dispersion of the maximum dielectric permittivity (epsilon[sup [prime]]) appears ar ... [Appl. Phys. Lett. 90, 112905 (2007)] published Tue Mar 13, 2007.
Alessandra Alberti, Corrado Spinella, Antonino La Magna, and Emanuele Rimini
... [Appl. Phys. Lett. 90, 119901 (2007)] published Tue Mar 13, 2007.
Samuel L. Mensah, Vijaya K. Kayastha, Ilia N. Ivanov, David B. Geohegan, and Yoke Khin Yap
Oxide and nitride nanotubes have gained attention for their large surface areas, wide energy band gaps, and hydrophilic natures for various innovative applications. These nanotubes were either grown by templates or multistep processes with uncontrollable crystallinity. Here the authors show that sin ... [Appl. Phys. Lett. 90, 113108 (2007)] published Tue Mar 13, 2007.
A. Yamamoto, A. Sawa, H. Akoh, M. Kawasaki, and Y. Tokura
Electrical properties of heteroepitaxial p-n junctions composed of correlated electron semiconductors La[sub 1x]Sr[sub x]FeO[sub 3] (LSFO) (x=0.4, 0.5, 0.67, and 0.8) and a band semiconductor SrTi[sub 0.99]Nb[sub 0.01]O[sub 3] were analyzed. The junctions exhibited rectifying current-voltage (I-V) c ... [Appl. Phys. Lett. 90, 112104 (2007)] published Tue Mar 13, 2007.
Z. D. Han, D. H. Wang, C. L. Zhang, H. C. Xuan, B. X. Gu et al.
... [Appl. Phys. Lett. 90, 119902 (2007)] published Tue Mar 13, 2007.
Wei Wei, S. L. Parker, Y.-M. Sun, J. M. White, Gang Xiong et al.
Photoemission electron microscopy is used to study copper diffusion through a ruthenium thin film. The photoemission electron microscopy images display a large contrast between Cu and Ru due to the differences in work function, making photoemission electron microscopy an ideal methodology to study t ... [Appl. Phys. Lett. 90, 111906 (2007)] published Tue Mar 13, 2007.
W. S. Lau, T. S. Tan, Premila Babu, and Nathan P. Sandler
In this letter, the authors will point out that defect states related to oxygen vacancies in tantalum oxide capacitors can be suppressed by titanium doping, resulting in significant leakage current reduction. The theory is that titanium forms an acceptor which can move at high temperature and neutra ... [Appl. Phys. Lett. 90, 112903 (2007)] published Tue Mar 13, 2007.
Xiaolong Wang and Ray T. Chen
A design of multimode interference coupler with deeply etched air trenches at the boundary of the multimode section is proposed for photonic integrated circuitry on low-index-contrast materials. The device length decreases from 820 to 750 [mu]m for a 1 x 8 polymer multimode interference coupler. ... [Appl. Phys. Lett. 90, 111106 (2007)] published Tue Mar 13, 2007.
F. Berkemeier, M. Shoar Abouzari, and G. Schmitz
Lithium borate network glasses are possible candidates for separator membranes in all-solid-state batteries. Thin films of a Li[sub 2]O-borate glass were produced by argon beam sputtering and their specific ionic conductivities were measured by impedance spectroscopy. The conductivity of as-sputtere ... [Appl. Phys. Lett. 90, 113110 (2007)] published Tue Mar 13, 2007.
Luigi Rigon, Fulvia Arfelli, and Ralf-Hendrik Menk
As different methods to improve diffraction enhanced imaging are proposed, the authors introduce a simple algorithm that follows the original idea of Chapman et al. [Phys. Med. Biol. [bold 42], 2015 (1997)], but extend it to a general object featuring absorption, refraction, and ultrasmall-angle sca ... [Appl. Phys. Lett. 90, 114102 (2007)] published Tue Mar 13, 2007.
Dongkyu Lee, Eun-Ha Kim, Myungsun Yoo, Namchul Jung, Kun-Hong Lee et al.
A thin catalytic layer of nickel was evaporated onto one side of silicon microcantilevers and amorphous silicon nanowires were synthesized on the nickel surface. When nanowire-grown cantilevers were exposed to mercaptohexanol vapor, their mass sensitivity was almost two orders of magnitude greater t ... [Appl. Phys. Lett. 90, 113107 (2007)] published Tue Mar 13, 2007.
Michael R. Armstrong, Bryan W. Reed, Ben R. Torralva, and Nigel D. Browning
Many pivotal aspects of material science, biomechanics, and chemistry would benefit from nanometer imaging with ultrafast time resolution. Here the authors demonstrate the feasibility of short-pulse electron imaging with 10 nm/10 ps spatiotemporal resolution, sufficient to characterize phenomena t ... [Appl. Phys. Lett. 90, 114101 (2007)] published Tue Mar 13, 2007.
G. Raino, G. Visimberga, A. Salhi, M. De Vittorio, A. Passaseo et al.
The authors have performed time resolved photoluminescence measurements by upconversion technique on InAs quantum dots embedded in an InGaAs/GaAs quantum well emitting at 1.3 [mu]m at room temperature. A detailed analysis of the photoluminescence transients as a function of the excitation density a ... [Appl. Phys. Lett. 90, 111907 (2007)] published Tue Mar 13, 2007.
Apurba Laha, H. J. Osten, and A. Fissel
The authors report on the impact of interface layer composition on electrical properties of epitaxial Gd[sub 2]O[sub 3] thin films on Si(001) substrates. The electrical properties of epitaxial Gd[sub 2]O[sub 3] thin films were improved significantly by controlled modification of interface layer comp ... [Appl. Phys. Lett. 90, 113508 (2007)] published Tue Mar 13, 2007.
Jae-Hyeon Ko, Do Han Kim, and Seiji Kojima
Acoustic properties of Pb[(Zn[sub 1/3]Nb[sub 2/3])[sub 0.91]Ti[sub 0.09]]O[sub 3] have been investigated in a wide temperature range. The sound velocity of acoustic phonons showed a deviation from its high-temperature linear behavior at the Burns temperature T[sub B]~730 K. Upon cooling, acoustic p ... [Appl. Phys. Lett. 90, 112904 (2007)] published Tue Mar 13, 2007.
Jian Wang, Xu-Cun Ma, Yun Qi, Ying-Shuang Fu, Shuai-Hua Ji et al.
Using a low temperature method, the authors have prepared atomically flat Pb ultrathin films on Si(111)-7 x 7 surface. Room temperature annealing of the films results in a percolation morphology with fractal vacancy islands where the Si substrate is exposed. The fractal film with a nominal thickness ... [Appl. Phys. Lett. 90, 113109 (2007)] published Tue Mar 13, 2007.
Journal of Applied Physics (JAP)
Nanoparticle decoration of ferroelectric domain patterns in LiNbO[sub 3] crystal
C. Ke, X. Wang, X. P. Hu, S. N. Zhu, and M. Qi
A scatheless visualization has demonstrated that the engineered and spontaneous domains of lithium niobate (LiNbO[sub 3]) crystal can be delineated by means of the nanoparticle decoration. These nanoparticles were monodispersed in nonpolar solvent and negatively charged under the existence of aeroso ... [J. Appl. Phys. 101, 064107 (2007)] published Thu Mar 22, 2007.
The effect of deposition rate on the intrinsic stress in copper and silver thin films
A. L. Del Vecchio and F. Spaepen
The effect of changing the deposition rate on the development of stress in evaporated copper and silver thin films deposited on oxidized silicon was examined. In situ stress measurements were made during deposition in ultrahigh vacuum using a scanning laser curvature system. In some experiments, the ... [J. Appl. Phys. 101, 063518 (2007)] published Thu Mar 22, 2007.
Magnetoelectric effect in laminate composites of Tb[sub 1 - x]Dy[sub x]Fe[sub 2 - y] and Fe-doped BaTiO[sub 3]
Ning Zhang, Junfeng Fan, Xiaofang Rong, Hongxia Cao, and Jianjun Wei
Fe-doped BaTiO[sub 3] has been synthesized with sol-gel technique. Its transformation point of ferroelectric to paraelectric and the latent heat of the transformation were observed at 103.27 degrees C and 169.9 J/mol, respectively. They are a little less than those for pure BaTiO[sub 3]. Bonded lay ... [J. Appl. Phys. 101, 063907 (2007)] published Thu Mar 22, 2007.
Purity assessment of multiwalled carbon nanotubes by Raman spectroscopy
Roberta A. DiLeo, Brian J. Landi, and Ryne P. Raffaelle
Carbonaceous purity assessment for chemical vapor deposition multiwalled carbon nanotubes (MWNTs) using Raman spectroscopy was investigated. Raman spectroscopy was performed on a reference sample set containing predetermined ratios of MWNTs and representative synthesis by-products. Changes in the ch ... [J. Appl. Phys. 101, 064307 (2007)] published Thu Mar 22, 2007.
[bold Investigation of the dielectric response in ]PbNb[sub 2]O[sub 6] ferroelectric ceramics
Y. Leyet, F. Guerrero, J. de Los S. Guerra, M. Venet, and J. A. Eiras
High Curie temperature ferroelectrics are promising materials to construct transducers for high-temperature piezoelectric applications. Among them, the lead niobate system is one that displays such characteristic. In this work, the dielectric behavior of lead niobate ferroelectric ceramics was analy ... [J. Appl. Phys. 101, 064105 (2007)] published Thu Mar 22, 2007.
All-ion accelerators: An injector-free synchrotron
Ken Takayama, Yoshio Arakida, Taiki Iwashita, Yoshito Shimosaki, Tanuja Dixit et al.
A medium-energy synchrotron capable of accelerating all-ion species is proposed. The accelerator employs a strong focusing lattice for ion-beam guiding and induction acceleration for acceleration and longitudinal capture, which is driven by a switching power supply. All ions, including cluster ions ... [J. Appl. Phys. 101, 063304 (2007)] published Thu Mar 22, 2007.
Effects of pretreatment processes on improving the formation of ultrananocrystalline diamond
Li-Ju Chen, Nyan-Hwa Tai, Chi-Young Lee, and I-Nan. Lin
Effects of pretreatment on the nuclei formation of ultrananocrystalline diamond (UNCD) on Si substrates were studied. Either precoating a thin layer of titanium (~400 nm) or ultrasonication pretreatment using diamond and titanium mixed powder (D&T process) enhances the nucleation process on Si subs ... [J. Appl. Phys. 101, 064308 (2007)] published Thu Mar 22, 2007.
Design of acoustic wave biochemical sensors using micro-electro-mechanical systems
Jane E. Valentine, Todd M. Przybycien, and Steinar Hauan
Acoustic wave biochemical sensors work by detecting the frequency shifts resulting from the binding of target molecules to a functionalized resonator. Resonator types currently in use or under development include macroscopic quartz crystal microbalances (QCMs) as well as a number of different integr ... [J. Appl. Phys. 101, 064508 (2007)] published Thu Mar 22, 2007.
Observation of localized charge transport in isolated microscopic mats of single-wall carbon nanotubes
Brian B. Glover and W. Lee Perry
We have formulated a composite consisting of a low dielectric permittivity, low loss granular organic crystal, and 0.1% single-walled carbon nanotubes (SWNTs). The composite morphology was electrically isolated mats of SWNTs distributed on the surface of individual crystals having a typical particle ... [J. Appl. Phys. 101, 064309 (2007)] published Thu Mar 22, 2007.
Self-organization of gold nanoclusters on hexagonal SiC and SiO[sub 2] surfaces
F. Ruffino, A. Canino, M. G. Grimaldi, F. Giannazzo, C. Bongiorno et al.
Very thin Au layers were deposited on SiC hexagonal and SiO[sub 2] substrates by sputtering. The Au surface diffusion, clustering, and self-organization of Au nanoclusters on these substrates, induced by thermal processes, were investigated by Rutherford backscattering spectrometry, atomic force mic ... [J. Appl. Phys. 101, 064306 (2007)] published Thu Mar 22, 2007.
Regrowth of diluted magnetic semiconductor GaMnAs on InGaP (001) surfaces to realize freestanding micromechanical structures
Hyung Kook Choi, Joon Sue Lee, Sung Woon Cho, Won Oh Lee, Seung Bo Shim et al.
Low temperature molecular beam epitaxy regrowths of Ga[sub 1x]Mn[sub x]As (x[approximate]0.04) diluted magnetic semiconductors on GaAs/In[sub 1y]Ga[sub y]P/GaAs(001) and In[sub 1y]Ga[sub y]P/GaAs(001) (y[approximate]0.51) heterostructures prepared by metal-organic chemical vapor deposition are descr ... [J. Appl. Phys. 101, 063906 (2007)] published Thu Mar 22, 2007.
Use of the point defect model to interpret the iron oxidation kinetics under proton irradiation
S. Lapuerta, N. Moncoffre, H. Jaffrezic, N. Millard-Pinard, N. Bererd et al.
This article concerns the study of iron corrosion in wet air under mega-electron-volt proton irradiation for different fluxes at room temperature and with a relative humidity fixed to 45%. Oxidized iron sample surfaces are characterized by ion beam analysis (Rutherford backscattering spectrometry an ... [J. Appl. Phys. 101, 064905 (2007)] published Thu Mar 22, 2007.
Evolution of nanodomains in 0.9PbMg[sub 1/3]Nb[sub 2/3]O[sub 3]-0.1PbTiO[sub 3] single crystals
V. V. Shvartsman and A. L. Kholkin
High-resolution studies of polar structures have been performed on the 0.9Pb(Mg[sub 1/3]Nb[sub 2/3])O[sub 3]-0.1PbTiO[sub 3] (0.9PMN-0.1PT) single crystals by piezoresponse force microscopy. A complex pattern of nanosized polar regions (nanodomains) was observed above the temperature of the structur ... [J. Appl. Phys. 101, 064108 (2007)] published Thu Mar 22, 2007.
Thermal stability of Er[sub 2]O[sub 3] thin films grown epitaxially on Si substrates
Sheng Chen, Yanyan Zhu, Rong Wu, Yueqin Wu, Yongliang Fan et al.
The thermal stability of Er[sub 2]O[sub 3] thin films grown epitaxially on Si substrates has been investigated in this paper by x-ray diffraction and high resolution transmission electron microscopy. The Er[sub 2]O[sub 3]/Si(001) films are found to react with Si to form silicates at the temperature ... [J. Appl. Phys. 101, 064106 (2007)] published Thu Mar 22, 2007.
Growth, spectral properties, and laser demonstration of Yb[sup 3+]:BaGd[sub 2](MoO[sub 4])[sub 4] cleavage crystal
Haomiao Zhu, Yujin Chen, Yanfu Lin, Xinghong Gong, Qiguang Tan et al.
Detailed polarized spectral properties of a 3.6 at. % Yb[sup 3+]:BaGd[sub 2](MoO[sub 4])[sub 4] (Yb[sup 3+]:BGM) cleavage crystal grown by the Czochralski method have been investigated, including the absorption cross section, the emission cross-section, and the fluorescence lifetime. The evaluation ... [J. Appl. Phys. 101, 063109 (2007)] published Thu Mar 22, 2007.
Magneto-optic properties of CoFe[sub 2 - x]Ga[sub x]O[sub 4]
S. J. Lee, S. H. Song, C. C. Lo, S. T. Aldini, and D. C. Jiles
Research on cobalt ferrite based composites has increased recently due to their potential applications such as noncontact magnetoelastic stress or torque sensors and erasable magneto-optic recording media. We report a study of the polar Kerr rotation spectra for CoFe[sub 2x]Ga[sub x]O[sub 4] (with x ... [J. Appl. Phys. 101, 09C502 (2007)] published Thu Mar 22, 2007.
High-pressure high-temperature synthesis and magnetic properties of ordered perovskite Sr[sub 2]Cu(Re[sub 0.69 - x]W[sub x]Ca[sub 0.31])O[sub 6] (0 <= x <= 0.6)
S. Balamurugan, M. Isobe, and E. Takayama-Muromachi
We report the synthesis and magnetic properties of polycrystalline Sr[sub 2]Cu(Re[sub 0.69x]W[sub x]Ca[sub 0.31])O[sub 6] samples with x=0, 0.1, 0.2, 0.3, 0.4, 0.5, and 0.6, which were prepared by high-pressure high-temperature synthesis technique. These phases had ordered cubic perovskite structure ... [J. Appl. Phys. 101, 09N501 (2007)] published Thu Mar 22, 2007.
Compression-induced texture change in NiMnGa-polymer composites observed by synchrotron radiation
Nils Scheerbaum, Dietrich Hinz, Oliver Gutfleisch, Werner Skrotzki, and Ludwig Schultz
Composites consisting of magnetic shape memory (MSM) particles embedded in a polyester matrix were prepared. Single-crystalline MSM particles were obtained by mortar grinding of melt-extracted and subsequently annealed Ni[sub 50.9]Mn[sub 27.1]Ga[sub 22.0] (at. %) fibers. The crystal structure of the ... [J. Appl. Phys. 101, 09C501 (2007)] published Thu Mar 22, 2007.
A phase diagram for the Bose-Einstein condensation of magnons
L. H. Bennett, E. Della Torre, P. R. Johnson, and R. E. Watson
Evidence has recently been given for the Bose-Einstein condensation (BEC) of magnons in nanostructures. This behavior occurs for nanoparticles some tens of nanometers in size (having some millions of atoms in a nanoparticle). Here we explore the effect of particle size on the BEC critical temperatur ... [J. Appl. Phys. 101, 09G103 (2007)] published Thu Mar 22, 2007.
Pulsed inductive measurement of ultrafast magnetization dynamics in interlayer exchange coupled NiFe/Ru/NiFe films
T. Martin, M. Belmeguenai, M. Maier, K. Perzlmaier, and G. Bayreuther
Pulsed inductive microwave magnetometer (PIMM), conventional ferromagnetic resonance (FMR), and vector network analyzer FMR (VNA-FMR), as well as quasistatic methods such as a magneto-optic Kerr effect magnetometer and a vibrating sample magnetometer, have been used for complementary studies of inte ... [J. Appl. Phys. 101, 09C101 (2007)] published Thu Mar 22, 2007.
A possible realization of spin filter using a quantum wire with Rashba spin-orbit coupling
Genhua Liu and Guanghui Zhou
We study theoretically the spin-polarized electron transport properties for a weak Rashba spin-orbit coupling (SOC) quantum wire connected nonadiabatically to two normal-conductor electrode leads. The influence of both the mode mixing due to wire-lead connection and Rashba SOC split on the spin-pola ... [J. Appl. Phys. 101, 063704 (2007)] published Wed Mar 21, 2007.
Stress-induced deceleration of electromigration-driven void motion in metallic thin films
M. Rauf Gungor and Dimitrios Maroudas
We report effects of biaxially applied stress on the electromigration-driven motion of morphologically stable voids in elastically deforming metallic thin films based on self-consistent numerical simulations of void evolution. We find that under certain electromechanical conditions, the applied stre ... [J. Appl. Phys. 101, 063513 (2007)] published Wed Mar 21, 2007.
The effect of nitrogen incorporation on the bonding structure of hydrogenated carbon nitride films
M. Camero, J. G. Buijnsters, C. Gomez-Aleixandre, R. Gago, I. Caretti et al.
This work describes the composition and bonding structure of hydrogenated carbon nitride (a-CN[sub x]:H) films synthesized by electron cyclotron resonance chemical vapor deposition using as precursor gases argon, methane, and nitrogen. The composition of the films was derived from Rutherford backsca ... [J. Appl. Phys. 101, 063515 (2007)] published Wed Mar 21, 2007.
Enhanced magnetoresistance of La[sub 2/3]Ca[sub 1/3]MnO[sub 3]/CeO[sub 2] nanocystalline composites synthesized by polymer-network gel method
L. D. Yao, W. Zhang, J. S. Zhang, H. Yang, F. Y. Li et al.
Using a dispersing particle polymer-network gel method, we prepared xLa[sub 2/3]Ca[sub 1/3]MnO[sub 3]/(1x)CeO[sub 2] nanocystalline composites, where the average grain sizes of La[sub 2/3]Ca[sub 1/3]MnO[sub 3] and CeO[sub 2] are about 30 nm and less than 10 nm, respectively. The magnetoresistance ... [J. Appl. Phys. 101, 063905 (2007)] published Wed Mar 21, 2007.
X-ray reciprocal space maps and x-ray scattering topographic observation of GaN layer on GaAs (001) in plasma-assisted molecular beam epitaxy
Yoshifumi Suzuki, Masakazu Shinbara, Hideki Kii, and Yoshinori Chikaura
We have characterized plasma-assisted N[sup +] molecular beam epitaxy-grown polymorphous GaN epitaxial layer on GaAs by x-ray reciprocal mapping using four-circle x-ray diffractometer and a personal computer controlled x-ray scattering topography system by ourselves. x-ray reciprocal mapping indicat ... [J. Appl. Phys. 101, 063516 (2007)] published Wed Mar 21, 2007.
Dependence of Langmuir probe data on distance from the axis of a collisionless plasma
Scott Knappmiller and Scott Robertson
A cylindrical Langmuir probe in a low-density, collisionless plasma (density ~10[sup 8] cm[sup 3], electron temperature 0.2 eV) has been scanned radially through the presheath region to determine the effect of distance from the axis on the current-voltage characteristic. In the ion part of the probe ... [J. Appl. Phys. 101, 063303 (2007)] published Wed Mar 21, 2007.
Analysis of vertical alignment and bending of crystalline alpha-Fe[sub 2]O[sub 3] nanowires using normal and grazing incidence x-ray diffraction intensities
U. P. Deshpande, T. Shripathi, D. Jain, A. V. Narlikar, S. K. Deshpande et al.
Owing to the increasing importance of orderly placed nanostructures, the following study was conducted on oriented and disoriented nanowires. Use of grazing incidence x-ray diffraction (GIXRD) and normal x-ray diffraction (XRD) as possible tools to assess their alignment is discussed. The property o ... [J. Appl. Phys. 101, 064304 (2007)] published Wed Mar 21, 2007.
Finite element analysis of resistivity measurement with four point probe in a diamond anvil cell
Xiaowei Huang, Chunxiao Gao, Ming Li, Chunyuan He, Aimin Hao et al.
Using finite element analysis, we studied the steady current field distribution under the configuration of four point probe method for resistivity measurement in a diamond anvil cell (DAC). Based on the theoretical analysis, we made a correction to the formula by Valdes [L. B. Valdes, Proc IRE, [bol ... [J. Appl. Phys. 101, 064904 (2007)] published Wed Mar 21, 2007.
Modeling and simulation of axisymmetric coating growth on nanofibers
K. Moore, C. B. Clemons, K. L. Kreider, and G. W. Young
This work is a modeling and simulation extension of an integrated experimental/modeling investigation of a procedure to coat nanofibers and core-clad nanostructures with thin film materials using plasma enhanced physical vapor deposition. In the experimental effort, electrospun polymer nanofibers ar ... [J. Appl. Phys. 101, 064305 (2007)] published Wed Mar 21, 2007.
Void growth by dislocation-loop emission
D. C. Ahn, P. Sofronis, M. Kumar, J. Belak, and R. Minich
Experimental results from spall tests on aluminum reveal the presence of a dense dislocation structure in an annulus around a void that grew under the tensile pulse when a shock wave was reflected at the free surface of the specimen. The proposition is that dislocation emission from the void surface ... [J. Appl. Phys. 101, 063514 (2007)] published Wed Mar 21, 2007.
Effect of a MgO interlayer on the structural and magnetic properties of Co[sub 2]Cr[sub 0.6]Fe[sub 0.4]Al thin films epitaxially grown on GaAs substrates
T. Yano, T. Uemura, K.-i. Matsuda, and M. Yamamoto
The effect of a MgO interlayer on the structural and magnetic properties of Co[sub 2]Cr[sub 0.6]Fe[sub 0.4]Al (CCFA) thin films epitaxially grown on GaAs substrates by sputtering was investigated. When the MgO interlayer thickness was 1.0 nm or less, the CCFA films were grown with a cube-on-cube re ... [J. Appl. Phys. 101, 063904 (2007)] published Wed Mar 21, 2007.
Prediction of B--Si[sub i]--F complex formation and its role in B transient enhanced diffusion suppression and deactivation
Scott A. Harrison, Thomas F. Edgar, and Gyeong S. Hwang
Gradient corrected density functional calculations are used to examine the interaction of boron and fluorine in crystalline silicon. We have determined the formation of a stable boron-silicon-fluorine (B[sub s]Si[sub i]F[sub i]) complex in which the B and F atoms are indirectly connected through a S ... [J. Appl. Phys. 101, 066102 (2007)] published Wed Mar 21, 2007.
Barkhausen noise in variable thickness amorphous finemet films
Ezio Puppin, Ermanno Pinotti, and Massimiliano Brenna
We measured the statistical properties of Barkhausen noise in finemet films with nominal composition Fe[sub 73.5]Cu[sub 1]Nb[sub 3]Si[sub 22.5]B[sub 4] and variable thickness between 25 and 1000 nm. Films have been sputtered on glass substrates and their structure is amorphous. The critical exponen ... [J. Appl. Phys. 101, 063903 (2007)] published Wed Mar 21, 2007.
The low-temperature photochromic and photorefractive response of bismuth germanium oxide doped with molybdenum
Adam W. Wood, C. A. Hunt, and J. J. Martin
Doping the photorefractive material bismuth germanium oxide, Bi[sub 12]GeO[sub 20] (BGO), with the 4d atom molybdenum introduces only a small shift to lower energy in the absorption cutoff in as-grown or well-annealed samples. Exposing a Mo-doped sample to blue-green light at 80 K superimposes an a ... [J. Appl. Phys. 101, 063517 (2007)] published Wed Mar 21, 2007.
Microstructure and mechanical property characterizations of metal foil after microscale laser dynamic forming
Gary J. Cheng, Daniel Pirzada, and Zhou Ming
This article discusses the feasibility of a new microforming techniquelaser dynamic forming (LDF). LDF is a new hybrid forming process, combining the advantages of laser shock peening, and metal forming, with an ultra high strain rate forming utilizing laser shock waves. Experiments are conducted on ... [J. Appl. Phys. 101, 063108 (2007)] published Wed Mar 21, 2007.
Exchange bias in a nanocolumnar Ni[sub 80]Fe[sub 20]/ alpha-Fe[sub 2]O[sub 3] thin film
J. van Lierop, K.-W. Lin, Z.-Y. Guo, P.-H. Ko, and H. Ouyang
A Ni[sub 80]Fe[sub 20]/alpha-Fe[sub 2]O[sub 3] thin film has been deposited using a dual ion-beam deposition technique where the alpha-Fe[sub 2]O[sub 3] is formed in situ by O[sub 2] bombardment of pure Fe. AC susceptibility results indicate moment fluctuations at temperatures above 150 K. This beh ... [J. Appl. Phys. 101, 09E505 (2007)] published Wed Mar 21, 2007.
Noncollinear magnetism in Permalloy
Markus Eisenbach, G. Malcolm Stocks, and Don M. Nicholson
Permalloy is an important material in a wide variety of magnetic systems, most notably in giant-magnetoresistive read heads. However, despite this great interest, its properties are not fully understood. For an in depth analysis of important physical properties as, e.g., electric transport or magnet ... [J. Appl. Phys. 101, 09G503 (2007)] published Wed Mar 21, 2007.
Magnetism in coaxial palladium nanowires
D. A. Stewart
While bulk palladium is nonmagnetic, several recent studies have shown that magnetism can occur in hcp Pd films, fcc twinned Pd nanoparticles, and Pd atomic strands. These studies show that small changes in Pd atomic configurations can induce magnetic properties. This raises the question of whether ... [J. Appl. Phys. 101, 09D503 (2007)] published Wed Mar 21, 2007.
Latent heat of the fcc Ising antiferromagnet
A. D. Beath and D. H. Ryan
To obtain critical parameters of the fcc Ising antiferromagnet from Monte Carlo data, a numerical estimate of the latent heat Delta is required. The precision of current estimates is about 3%, and ultimately limits the precision achieved for the disordered state at the Neel temperature T[sub N]. Her ... [J. Appl. Phys. 101, 09G102 (2007)] published Wed Mar 21, 2007.
Antiferromagnetic interlayer coupling through a thin MgO layer in gamma-Fe[sub 2]O[sub 3]/MgO/Fe(001) multilayers
H. Yanagihara, Yuta Toyoda, and Eiji Kita
We investigated the magnetization process of epitaxial MgO(001)/gamma-Fe[sub 2]O[sub 3]/MgO/Fe(001) multilayers. When the thickness of a MgO spacer layer was less than 1.0 nm, an antiferromagnetic interlayer exchange coupling (IEC) between Fe(001) and gamma-Fe[sub 2]O[sub 3](001) layers appeared. U ... [J. Appl. Phys. 101, 09D101 (2007)] published Wed Mar 21, 2007.
Analysis of the size effect in electroplated fine copper wires and a realistic assessment to model copper resistivity
W. Zhang, S. H. Brongersma, Z. Li, D. Li, O. Richard et al.
The size effect in electroplated copper wires has been widely studied recently. However, there is no consensus on the role of various scattering mechanisms. Therefore, an in-depth analysis to reveal the origin of the size effect is needed. In this article, we study the resistivity of fine copper wir ... [J. Appl. Phys. 101, 063703 (2007)] published Tue Mar 20, 2007.
Laser sintering of thick-film conductors for microelectronic applications
Edward C. Kinzel, Hjalti H. Sigmarsson, Xianfan Xu, and William J. Chappell
This paper investigates fabrication of functional thick metal films using simultaneous laser sintering and patterning along with the fundamental physical phenomena that govern the laser sintering process. The effects of the processing parameters on the quality of the fabricated components are invest ... [J. Appl. Phys. 101, 063106 (2007)] published Tue Mar 20, 2007.
Modeling nonisothermal interaction kinetics in the condensed state: A diagram of phase formation mechanisms for the Ni--Al system
Boris B. Khina
Nonisothermal interaction in condensed NiAl system takes place during combustion synthesis (CS) or the so-called self-propagating high-temperature synthesis, which is characterized by a high heating rate, high final temperature, fast accomplishment of interaction, and unconventional, nonequilibrium ... [J. Appl. Phys. 101, 063510 (2007)] published Tue Mar 20, 2007.
Artifacts identification in apertureless near-field optical microscopy
P. G. Gucciardi, G. Bachelier, M. Allegrini, J. Ahn, M. Hong et al.
The aim of this paper is to provide criteria for optical artifacts recognition in reflection-mode apertureless scanning near-field optical microscopy, implementing demodulation techniques at higher harmonics. We show that optical images acquired at different harmonics, although totally uncorrelated ... [J. Appl. Phys. 101, 064303 (2007)] published Tue Mar 20, 2007.
Carrier trapping effects on photoluminescence decay time in InGaN/GaN quantum wells with nanocluster structures
Yen-Cheng Lu, Cheng-Yen Chen, Hsiang-Chen Wang, C. C. Yang, and Yung-Chen Cheng
Carrier dynamics in InGaN/GaN quantum wells (QWs) with compositional fluctuations is studied with time-resolved photoluminescence (PL) experiments and Monte Carlo simulations of exciton hopping and recombination. In particular, the effects of indium-rich nanoclusters in such a QW structure on the ph ... [J. Appl. Phys. 101, 063511 (2007)] published Tue Mar 20, 2007.
A conceptual model of light coupling by pillar diffraction gratings
K. R. Catchpole and M. A. Green
Diffractive structures such as pillar gratings are a promising way of coupling light into or out of thin semiconductor devices, for applications in thin film solar cells and light-emitting diodes. In this paper we show that the diffuse transmittance behavior of pillar gratings can be understood usin ... [J. Appl. Phys. 101, 063105 (2007)] published Tue Mar 20, 2007.
Long wavelength bulk GaInNAs p - i - n photodiodes lattice matched to GaAs
J. S. Ng, W. M. Soong, M. J. Steer, M. Hopkinson, J. P. R. David et al.
We report bulk GaInNAs pin photodiodes lattice-matched to GaAs substrates, grown by solid source molecular beam epitaxy with photoresponses out to ~1.3 [mu]m. The as-grown samples were characterized optically, structurally, and electrically. A low background doping concentration in the range of 10[s ... [J. Appl. Phys. 101, 064506 (2007)] published Tue Mar 20, 2007.
Hybrid metallic nanoparticles for excitation of surface plasmon resonance
Shaoli Zhu, Xiangang Luo, Chunlei Du, Fei Li, Shaoyun Yin et al.
A Ag nanostructure was put forward in this paper. There are two types of Ag nanoparticles, spherical and pyramidal particles. Both of them have the same period, but different height and shapes. The hybrid nanoparticles can produce the localized surface plasmon resonance (LSPR), which couples each ot ... [J. Appl. Phys. 101, 064701 (2007)] published Tue Mar 20, 2007.
Electrostatically actuated conducting polymer microbridges
G. Zhang, V. Chu, and J. P. Conde
All-polymer microbridge electrostatic actuators based on a blended conductive polymer are fabricated using surface micromachining on glass substrates. A fabrication process is developed that allows the preservation of the electrical conductivity of the polymer structural layer and the suspension of ... [J. Appl. Phys. 101, 064507 (2007)] published Tue Mar 20, 2007.
Electric field effect analysis of thin PbTe films on high-epsilon SrTiO[sub 3] substrate
A. V. Butenko, R. Kahatabi, V. Sandomirsky, Y. Schlesinger, A. Yu. Sipatov et al.
Thin PbTe films (thickness 500600 A), deposited on SrTiO[sub 3], have been investigated by electric field effect (EFE). The high resistivity of such thin films warrants a high sensitivity of the EFE method. The SrTiO[sub 3] substrate serves as the dielectric layer in the gate-dielectric-PbTe struct ... [J. Appl. Phys. 101, 064104 (2007)] published Tue Mar 20, 2007.
Microstructural and optical properties of Ba[sub 0.5]Sr[sub 0.5]TiO[sub 3] thin film deposited by pulsed laser deposition for low loss waveguide applications
M. Gaidi, M. Chaker, P. F. Ndione, R. Morandotti, and B. Bessais
Barium strontium titanate (Ba[sub 0.5]Sr[sub 0.5]TiO[sub 3] or BST) films were grown on SiO[sub 2]/Si substrate by means of a reactive pulsed laser deposition technique. The microstructural and surface morphology of BST films were characterized by x-ray diffraction, scanning electron microscopy, and ... [J. Appl. Phys. 101, 063107 (2007)] published Tue Mar 20, 2007.
Effective mass density of liquid composites: Experiment and theory
W. Z. Yang and J. P. Huang
We present an effective medium theory based on the Maxwell-Garnett [J. C. Maxwell Garnett, Philos. Trans. R. Soc. London, Ser. A [bold 203], 385 (1904); ibid. [bold 205], 237 (1906)] and Bruggeman [D. A. G. Bruggeman, Ann. Phys. (Leipzig) [bold 24], 636 (1935)] approximations, to investigate the ef ... [J. Appl. Phys. 101, 064903 (2007)] published Tue Mar 20, 2007.
Low-T[sub c] Josephson junctions with tailored barrier
M. Weides, C. Schindler, and H. Kohlstedt
Nb/Al[sub 2]O[sub 3]/Ni[sub 0.6]Cu[sub 0.4]/Nb based superconductor-insulator-ferromagnet-superconductor Josephson tunnel junctions with a thickness step in the metallic ferromagnetic Ni[sub 0.6]Cu[sub 0.4] interlayer were fabricated. The step was defined by optical lithography and controlled etchin ... [J. Appl. Phys. 101, 063902 (2007)] published Tue Mar 20, 2007.
Structural stability and characteristics of the metastable Ag--W phases studied by ab initio and molecular dynamics calculations
X. D. Dai, J. H. Li, H. B. Guo, and B. X. Liu
For the immiscible AgW system, ab initio calculations identify the relatively stable structures of the metastable Ag[sub 75]W[sub 25], AgW, and Ag[sub 25]W[sub 75] phases to be L6[sub 0], B2, and L1[sub 2], respectively. Based on a newly derived AgW potential under an extended Finnis-Sinclair formal ... [J. Appl. Phys. 101, 063512 (2007)] published Tue Mar 20, 2007.
Submicron patterning of a catalyst film by scanning probe nanolithography for a selective chemical vapor deposition of carbon nanotubes
P. Parisse, A. Verna, M. Rinaldi, F. Bussolotti, V. Grossi et al.
Submicrometric catalyst patterns have been fabricated by atomic force nanolithography and the subsequent selective growth of carbon nanotubes has been successfully verified. Rectangular stripes (~350 nm wide) were engraved onto a polymethylmethacrylate film, deposited onto SiO[sub 2]/Si, by polymer ... [J. Appl. Phys. 101, 066101 (2007)] published Tue Mar 20, 2007.
Third harmonic generation in undoped and X doped ZnO films (X: Ce, F, Er, Al, Sn) deposited by spray pyrolysis
Zouhair Sofiani, Bouchta Sahraoui, Mohammed Addou, Rahma Adhiri, Mehdi Alaoui Lamrani et al.
There is a current interest in research of wide band gap semiconductor materials for the purposes of third order nonlinear optical properties in view of optoelectronics applications. Materials for nonlinear optics should present important changes of nonlinear intensity, dependence on changes of nonl ... [J. Appl. Phys. 101, 063104 (2007)] published Tue Mar 20, 2007.
Avalanche of flux jumps in polycrystalline MgB[sub 2] superconductor
I. Felner, V. P. S. Awana, Monika Mudgel, and H. Kishan
Dc magnetization studies were carried out on a polycrystalline MgB[sub 2] superconductor, which was synthesized at 750 degrees C in Fe tube encapsulation under a vacuum of 10[sup 5] Torr. Zero resistances at H=0 and 8 T are obtained at 38 and 22 K, respectively. The material possesses a sharp d ... [J. Appl. Phys. 101, 09G101 (2007)] published Tue Mar 20, 2007.
Giant uncompensated magnetization and exchange bias in Fe[sub x]Ni[sub 1 - x]F[sub 2]/Co bilayers
Miyeon Cheon, Zhongyuan Liu, and David Lederman
Fe[sub x]Ni[sub 1x]F[sub 2] is an antiferromagnet with a magnetic anisotropy that can be varied continuously by changing the concentration x. In studying the exchange bias of a polycrystalline Co grown on Fe[sub x]Ni[sub 1x]F[sub 2] (110) epitaxial films, a giant uncompensated magnetization, of up t ... [J. Appl. Phys. 101, 09E503 (2007)] published Tue Mar 20, 2007.
Fabrication of RE--Fe--B films with highly c-axis texture and excellent hard magnetic properties
S. L. Tang, M. R. J. Gibbs, H. A. Davies, Z. W. Liu, S. C. Lane et al.
REFeB films were prepared on a Ta buffer layer on thermally oxidized Si substrates by dc magnetron sputtering. The structure, magnetic structure, and magnetic properties of REFeB films were studied. The results show the preparation procedure of deposition at 470 degrees C to obtain a strong c-axis ... [J. Appl. Phys. 101, 09K501 (2007)] published Tue Mar 20, 2007.
Surface electronic structure and magnetism of NiAs structured MnAs(0001) and MnSb(0001)
J. I. Lee and S. C. Hong
We investigated the surface electronic structure and magnetism of the NiAs structured MnAs(0001) and MnSb(0001) using first-principles full-potential linearized augmented plane wave (FLAPW) method within the generalized gradient approximation. We considered the Mn- and anion(As or Sb)-terminated sur ... [J. Appl. Phys. 101, 09G502 (2007)] published Tue Mar 20, 2007.
Reactive sputtering synthesis of Co--CoO/Ag nanogranular and multilayer films containing core-shell particles
T. Munoz, J. A. De Toro, P. S. Normile, J. P. Andres, J. A. Gonzalez et al.
We present magnetic characterization of two series of samples grown by reactive sputtering of Co and Ag: (i) thin films obtained by cosputtering of these metals at different oxygen pressures, and (ii) Co/Ag multilayer films deposited with fixed Co layer thickness (1.1 nm) and oxygen pressure (2 x 1 ... [J. Appl. Phys. 101, 09E504 (2007)] published Tue Mar 20, 2007.
Influence of structural imperfection of Sigma 5 grain boundaries in bulk multicrystalline Si on their electrical activities
Kentaro Kutsukake, Noritaka Usami, Kozo Fujiwara, Yoshitaro Nose, and Kazuo Nakajima
Bulk multicrystalline Si with {310} Sigma5 grain boundaries (GBs) was grown by Bridgman growth method using seed crystals with artificially controlled configuration. The structure of the GBs was preserved in the epitaxial growth region without formation of more GBs. However, the GBs were revealed to ... [J. Appl. Phys. 101, 063509 (2007)] published Mon Mar 19, 2007.
Simplified description of microwave plasma discharge for chemical vapor deposition of diamond
Hideaki Yamada, Akiyoshi Chayahara, and Yoshiaki Mokuno
A fluid model to prescribe microwave plasma is proposed. The conservation equations for electron are reduced to only one differential equation. Therefore, the computational cost is also reduced as small as possible. One may extend functions of existing program for vacuum field analysis to microwave ... [J. Appl. Phys. 101, 063302 (2007)] published Mon Mar 19, 2007.
Deformation effect on electronic and optical properties of nanographite ribbons
C. P. Chang, B. R. Wu, R. B. Chen, and M. F. Lin
The electronic structures of deformed nanographite ribbons are calculated from the Huckel tight-binding model. They strongly depend on the uniaxial strain and the ribbon geometry (edge structure and width). The uniaxial strain significantly affects the subband spacings and the energy dispersions. A ... [J. Appl. Phys. 101, 063506 (2007)] published Mon Mar 19, 2007.
Infrared reflection spectra of Ba[sub 6 - 3x]Sm[sub 8 + 2x]Ti[sub 18]O[sub 54] (x = 0.5, 0.67, and 0.75) microwave dielectric ceramics
N. Qin, X. C. Fan, S. Y. Wu, and X. M. Chen
Infrared reflection spectra of the tungsten bronze-type Ba[sub 63x]Sm[sub 8+2x]Ti[sub 18]O[sub 54] (x=0.5, 0.67, and 0.75) ceramics were measured and analyzed by a combined method using Kramers-Kroning relation and the classical oscillator model, and the selection rules and vibration modes of the tu ... [J. Appl. Phys. 101, 064103 (2007)] published Mon Mar 19, 2007.
Effects of grains' features in surface roughness scaling
T. J. Oliveira and F. D. A. Aarao Reis
We study the local and global roughness scaling in growth models with grains at the film surfaces. The local roughness, measured as a function of window size r, shows a crossover at a characteristic length r[sub c], from a rapid increase with exponent alpha[sub 1] to a slower increase with exponent ... [J. Appl. Phys. 101, 063507 (2007)] published Mon Mar 19, 2007.
The imaging property of photoacoustic Fourier imaging and tomography using an acoustic lens imaging system
Wei Wan, Ruisheng Liang, Zhilie Tang, Zhanxu Chen, Hanchao Zhang et al.
The theory of photoacoustic tomography imaging using an acoustic lens imaging system has been investigated, and the photoacoustic (PA) Fourier imaging property of an acoustic lens is presented. The theoretical results show that an acoustic lens is able to realize two-dimensional PA Fourier imaging a ... [J. Appl. Phys. 101, 063103 (2007)] published Mon Mar 19, 2007.
Field emission from gadolinium silicide prepared by ion implantation with electron beam annealing
H. G. Duan, E. Q. Xie, and F. Ye
A silicon-based field emission cathode, the rare earth silicide GdSi[sub 2] was prepared by implanting Gd ions into silicon using a metal vapor vacuum arc ion source and subsequently annealed by electron beam. For as-implanted samples, turn-on field was about 21 V/[mu]m at a current density of 1 [ ... [J. Appl. Phys. 101, 064503 (2007)] published Mon Mar 19, 2007.
Experimentally validated quantitative linear model for the device physics of elastomeric microfluidic valves
Emil P. Kartalov, Axel Scherer, Stephen R. Quake, Clive R. Taylor, and W. French Anderson
A systematic experimental study and theoretical modeling of the device physics of polydimethylsiloxane pushdown microfluidic valves are presented. The phase space is charted by 1587 dimension combinations and encompasses 45295 [mu]m lateral dimensions, 1639 [mu]m membrane thickness, and 128 psi c ... [J. Appl. Phys. 101, 064505 (2007)] published Mon Mar 19, 2007.
Electronic structures of organic/organic heterojunctions: From vacuum level alignment to Fermi level pinning
J. X. Tang, C. S. Lee, and S. T. Lee
Electronic structures of organic/organic (O/O) heterojunctions have been studied by photoemission spectroscopy. We showed that vacuum level alignment is only valid for certain O/O heterojunctions rather than a general rule for organic junctions. The mode of energy level alignment is found to depend ... [J. Appl. Phys. 101, 064504 (2007)] published Mon Mar 19, 2007.
Zinc phosphate chain length study under high hydrostatic pressure by Raman spectroscopy
M. Gauvin, F. Dassenoy, C. Minfray, J. M. Martin, G. Montagnac et al.
The aim of this study is to combine a diamond anvil cell with in-situ Raman spectroscopy to simulate and analyze the effect of pure pressure on the length of phosphate chains in an antiwear film formed in a tribological contact. In-situ Raman spectra of Zn[sub 2]P[sub 2]O[sub 7] glass, alpha-Zn[sub ... [J. Appl. Phys. 101, 063505 (2007)] published Mon Mar 19, 2007.
Nonlinear spin wave magnetization of solution synthesized Ni nanoparticles
Satish Vitta
The magnetic properties of Ni nanoparticles synthesized using a soft chemical method followed by heat treatment in H[sub 2] atmosphere have been studied in detail. The powder consists of pure Ni with no additional phase and the average crystallite size is 305 nm, determined using the modified Scher ... [J. Appl. Phys. 101, 063901 (2007)] published Mon Mar 19, 2007.
Fabrication and characterization of TiSi[sub 2]/Si heteronanocrystal metal-oxide-semiconductor memories
Yan Zhu, Bei Li, and Jianlin Liu
TiSi[sub 2]/Si heteronanocrystals on ultrathin oxide was fabricated with self-aligned silicidation method. Compared with Si nanocrystal memory device, TiSi[sub 2]/Si heteronanocrystal metal-oxide-semiconductor memory device shows higher writing saturation level, faster writing/erasing speed, longer ... [J. Appl. Phys. 101, 063702 (2007)] published Mon Mar 19, 2007.
Low temperature magnetron sputter deposition of polycrystalline silicon thin films using high flux ion bombardment
Jennifer E. Gerbi and John R. Abelson
We demonstrate that the microstructure of polycrystalline silicon thin films depends strongly on the flux of low energy ions that bombard the growth surface during magnetron sputter deposition. The deposition system is equipped with external electromagnetic coils which, through the unbalanced magnet ... [J. Appl. Phys. 101, 063508 (2007)] published Mon Mar 19, 2007.
Photoconductivity in molecularly doped poly(methylmethacrylate) sandwich cells
V. C. Kishore, R. Dhanya, C. Sudha Kartha, K. Sreekumar, and Rani Joseph
Poly(methyl)methacrylate was made photoconducting by molecular doping and the photoconductivity was investigated using modulated photocurrent technique. Low-temperature current-voltage measurements showed that the transport mechanism was thermally activated hopping. An experimental investigation of ... [J. Appl. Phys. 101, 063102 (2007)] published Mon Mar 19, 2007.
Perpendicular exchange bias mechanism in FePt/FeMn multilayers
Nguyen N. Phuoc and Takao Suzuki
A systematic study of parallel and perpendicular exchange biases in FePt/FeMn multilayers fabricated onto MgO(001) substrates by ion beam sputter deposition system was conducted. The blocking temperature of parallel exchange bias was found to be higher than that of the perpendicular one. The discrep ... [J. Appl. Phys. 101, 09E501 (2007)] published Mon Mar 19, 2007.
Dynamical spin response of itinerant electrons close to a quantum critical point
P. Schlottmann
The dynamical spin susceptibility chi[sup [double-prime]](omega,[bold Q]), which is of relevance to inelastic neutron scattering, is calculated for an itinerant antiferromagnet (AF) close to a quantum critical point (QCP). The model consists of nested Fermi surfaces of an electron pocket and a hole ... [J. Appl. Phys. 101, 09G501 (2007)] published Mon Mar 19, 2007.
Heat capacity of pyrochlore Pr[sub 2]Ru[sub 2]O[sub 7]
Makoto Tachibana, Yoshimitsu Kohama, Tooru Atake, and Eiji Takayama-Muromachi
Heat capacity measurements have been performed from 0.4 to 200 K in 0 T and from 0.4 to 20 K in magnetic fields up to 9 T on the cubic pyrochlore compound Pr[sub 2]Ru[sub 2]O[sub 7]. The long-range antiferromagnetic ordering of the Ru[sup 4+] moments is accompanied by a sharp lambda-type ano ... [J. Appl. Phys. 101, 09D502 (2007)] published Mon Mar 19, 2007.
Influence of the domain structure of nano-oxide layers on the transport properties of specular spin valves
J. Ventura, J. B. Sousa, A. Veloso, and P. P. Freitas
Specular spin valves show enhanced giant magnetoresistive ratio when compared to other simpler, spin valve structures as a result of specular reflection in nano-oxide layers (NOLs) formed by the partial oxidation of the CoFe pinned and free layers. The oxides forming the NOL were recently shown to o ... [J. Appl. Phys. 101, 09E502 (2007)] published Mon Mar 19, 2007.
Switching speed distribution of spin-torque-induced magnetic reversal
J. He, J. Z. Sun, and S. Zhang
The switching probability of a single-domain ferromagnet under spin-current excitation is evaluated using the Fokker-Planck equation (FPE). In the case of uniaxial anisotropy, the FPE reduces to an ordinary differential equation in which the lowest eigenvalue lambda[sub 1] determines the slowest swi ... [J. Appl. Phys. 101, 09A501 (2007)] published Mon Mar 19, 2007.
Raman scattering spectra and ferroelectric properties of Bi[sub 1 - x]Nd[sub x]FeO[sub 3] (x = 0--0.2) multiferroic ceramics
G. L. Yuan, Siu Wing Or, and Helen Lai Wa Chan
Single-phase Bi[sub 1x]Nd[sub x]FeO[sub 3] (BNFO[sub x]) (x=00.2) multiferroic ceramics were prepared to study the effects of Nd substitution on their crystal structures, Raman scattering spectra, and ferroelectric properties. Rietveld refinement of x-ray diffraction data showed a gradual change in ... [J. Appl. Phys. 101, 064101 (2007)] published Fri Mar 16, 2007.
Strain relaxation in heteroepitaxial films by misfit twinning. I. Critical thickness
Lilin Liu, Yousheng Zhang, and Tong-Yi Zhang
Based on the dislocation theory of twinning, an analytical solution is given to determine the critical thickness of the misfit twin formation in an epilayer with different elastic constants from its substrate. For a given epilayer thickness and lattice mismatch strain, the twin formation energy shou ... [J. Appl. Phys. 101, 063501 (2007)] published Fri Mar 16, 2007.
Electrochemical preparation of a rugate filter in silicon and its deviation from the ideal structure
M. S. Salem, M. J. Sailor, T. Sakka, and Y. H. Ogata
Porous silicon single layers are formed by anodization of silicon in a hydrofluoric acid solution at different current densities. An accurate estimation of the etch rates and refractive indices is performed. The refractive index-depth profile of a porous silicon rugate filter (PSRF) prepared by sinu ... [J. Appl. Phys. 101, 063503 (2007)] published Fri Mar 16, 2007.
Thermal conductivity improvement in carbon nanoparticle doped PAO oil: An experimental study
S. Shaikh, K. Lafdi, and R. Ponnappan
The present work involves a study on the thermal conductivity of nanoparticle-oil suspensions for three types of nanoparticles, namely, carbon nanotubes (CNTs), exfoliated graphite (EXG), and heat treated nanofibers (HTT) with PAO oil as the base fluid. To accomplish the above task, an experimental ... [J. Appl. Phys. 101, 064302 (2007)] published Fri Mar 16, 2007.
Intra-atomic photoluminescence at 1.41 eV of substitutional Mn in GaMnN of high optical quality
J. Zenneck, T. Niermann, D. Mai, M. Roever, M. Kocan et al.
We report on a characteristic photoluminescence feature of the substitutional Mn in high quality GaMnN layers. The lattice site was identified using atom localization by channeling enhanced microanalysis with a transmission electron microscope. It shows that 96.5%5.0% of the Mn atoms are incorporate ... [J. Appl. Phys. 101, 063504 (2007)] published Fri Mar 16, 2007.
Evidence of nonclassical plasma transport in hollow cathodes for electric propulsion
Ioannis G. Mikellides, Ira Katz, Dan M. Goebel, and Kristina K. Jameson
Measurements, simplified analyses, and two-dimensional numerical simulations with a fluid plasma model show that classical resistivity cannot account for the elevated electron temperatures and steep plasma potential gradients measured in a 2527.5 A electric propulsion hollow cathode. The cathode co ... [J. Appl. Phys. 101, 063301 (2007)] published Fri Mar 16, 2007.
Temperature dependent characteristics of all polymer thin-film transistors based on poly(9,9-dioctylfluorene-co-bithiophene)
Feng Yan, Yi Hong, and Piero Migliorato
Thin-film transistors based on poly(9,9-dioctylfluorene-co-bithiophene) have been studied in the temperature range from 130 to 300 K. In this temperature range both the field effect mobility and the drain current show thermally activated behavior. From the bias and temperature dependence of the d ... [J. Appl. Phys. 101, 064501 (2007)] published Fri Mar 16, 2007.
In situ synchrotron x-ray photon beam characterization
Nicholas R. Kyele, Roelof G. van Silfhout, Spyros Manolopoulos, and S. Nikitenko
We have investigated two in situ methods of measuring x-ray beam parameters such as integrated intensity, position, and intensity distribution. These virtually transparent methods both rely on the collection of scattered radiation from a thin amorphous foil. The scattered radiation is collected by a ... [J. Appl. Phys. 101, 064901 (2007)] published Fri Mar 16, 2007.
p-type semiconducting alpha,omega-dihexylsexithiophene for an organic thin film transistor
Jae-Hong Kwon, Jung-Hoon Seo, Hochul Kang, Dong Hoon Choi, and Byeong-Kwon Ju
End substitution of sexithiophene with hexyl groups, alpha,omega-dihexylsexithiophene (DH-6T), leads to a highly soluble conjugated oligomer. In this paper, we report on the synthesis of an air-stable p-type organic semiconductor, DH-6T. We also report on our analysis of its thermal, optical, and el ... [J. Appl. Phys. 101, 064502 (2007)] published Fri Mar 16, 2007.
Skeletal Si--O--Si network connectivity of self-assembled porous silica for low-k dielectrics depending on organoalkoxysilane concentration in precursor solutions
Syozo Takada, Nobuhiro Hata, Kikuko Hayamizu, Miwa Murakami, Kenzo Deguchi et al.
Self-assembled porous silica films prepared from the tetraethoxysilane (TEOS)-based precursor solutions containing dimethyldiethoxysilane (DMDEOS) are known to have higher mechanical strength than the films prepared from TEOS precursor solution not containing DMDEOS. To clarify the origin of their h ... [J. Appl. Phys. 101, 064301 (2007)] published Fri Mar 16, 2007.
Strain relaxation in heteroepitaxial films by misfit twinning: II. Equilibrium morphology
Yousheng Zhang, Lilin Liu, and Tong-Yi Zhang
The equilibrium morphology of misfit twins in an epilayer with different elastic constants from its substrate is systematically investigated by energy minimization based on the dislocation mechanism of twinning. Explicit formulas for period arrays of misfit twins with the same orientation and with a ... [J. Appl. Phys. 101, 063502 (2007)] published Fri Mar 16, 2007.
Supersonic jet deposition of silver nanoparticle aerosols: Correlations of impact conditions and film morphologies
Chong Huang, William T. Nichols, Daniel T. O'Brien, Michael F. Becker, Desiderio Kovar et al.
We describe experiments and modeling for the deposition of silver lines and films via the impaction of a silver nanoparticle aerosol delivered through a supersonic jet. The aerosol gas dynamics of the jet flow field, nanoparticle acceleration in the jet, and deposition by impaction onto the substrat ... [J. Appl. Phys. 101, 064902 (2007)] published Fri Mar 16, 2007.
Annealing effect on dislocations in SrTiO[sub 3]/LaAlO[sub 3] heterostructures
Dong Su, Tomoaki Yamada, Vladimir O. Sherman, Alexander K. Tagantsev, Paul Muralt et al.
Epitaxial SrTiO[sub 3] thin films were deposited on (001) LaAlO[sub 3] single crystals by pulsed laser deposition. The postannealing effect was studied by annealing the deposited films at 1100 degrees C in O[sub 2] atmosphere for 4 h. It was found that the postannealing treatment enhances the in- ... [J. Appl. Phys. 101, 064102 (2007)] published Fri Mar 16, 2007.
Electrical characterization of alpha radiation-induced defects in p-GaAs grown by metal-organic chemical-vapor deposition
Nazir A. Naz, Umar S. Qurashi, and M. Zafar Iqbal
Investigations of the alpha particle irradiation-induced defects in low-pressure metal-organic chemical-vapor deposition grown p-GaAs have been carried out. By employing deep-level transient spectroscopy, at least seven radiation-induced deep-level defects have been observed in the lower half of the ... [J. Appl. Phys. 101, 063701 (2007)] published Fri Mar 16, 2007.
X-valley leakage in GaAs-based midinfrared quantum cascade lasers: A Monte Carlo study
X. Gao, D. Botez, and I. Knezevic
We present a detailed Monte Carlo simulation of electron transport incorporating both Gamma- and X-valley states in GaAs-based quantum cascade lasers (QCLs). Gamma states are calculated using the Kp method, while X states are obtained within the effective mass framework. All the relevant electron-ph ... [J. Appl. Phys. 101, 063101 (2007)] published Fri Mar 16, 2007.
Abnormal I-V characteristics and metal-insulator transition of Fe-doped amorphous carbon/silicon p-n junction
Lanzhong Hao, Qingzhong Xue, Xili Gao, Qun Li, Qingbin Zheng et al.
Simple p-C/n-Si junctions have been fabricated by magnetron sputtering at room temperature and their current-voltage (I-V) characteristics have been investigated. The p-n junctions show good rectifying properties in a large voltage scope and interesting I-V characteristics. The most interesting phen ... [J. Appl. Phys. 101, 053718 (2007)] published Thu Mar 15, 2007.
Spatially and temporally resolving the degradation of n-channel poly-Si thin-film transistors under hot-carrier stressing
Ming-Hsien Lee, Kai-Hsiang Chang, and Horng-Chih Lin
A test structure was proposed to investigate the spatial and temporal evolution of hot-carrier degradation in n-channel poly-Si thin-film transistors. Our experimental results clearly show that the initial damage during the early stage of hot-carrier stressing, which is still undetectable by convent ... [J. Appl. Phys. 101, 054518 (2007)] published Thu Mar 15, 2007.
Magnetization process in a ferromagnetic disk measured by a semiconductor two-dimensional electron gas
Masahiro Hara and Yoshichika Otani
We have monitored a magnetization process in a ferromagnetic disk by measuring a bend resistance of semiconductor two-dimensional electron gas (2DEG) lying beneath the disk. Annihilation and nucleation of a vortex in the ferromagnetic disk are clearly seen in the trace of the bend resistance as a fu ... [J. Appl. Phys. 101, 056107 (2007)] published Thu Mar 15, 2007.
Decay of zone-center phonons in GaN with A[sub 1], E[sub 1], and E[sub 2] symmetries
D. Y. Song, S. A. Nikishin, M. Holtz, V. Soukhoveev, A. Usikov et al.
We report Raman studies of the A[sub 1](TO), E[sub 1](TO), E[sub 2][sup 2], A[sub 1](LO), and E[sub 1](LO) symmetry phonons of GaN from 20 to 325 K. By applying anharmonic decay theory to the observed temperature dependences of the phonon energies and linewidths, we determine the phonon decay mec ... [J. Appl. Phys. 101, 053535 (2007)] published Thu Mar 15, 2007.
Polarized light emission from semipolar GaInN quantum wells on {1[overline 1]01} GaN facets
M. Feneberg, F. Lipski, R. Sauer, K. Thonke, P. Bruckner et al.
GaInN quantum wells with reduced piezoelectric field deposited epitaxially on the {1[overline 1]01} facets of selectively grown GaN stripes show distinct polarization properties of the emitted light. Systematic electro- and photoluminescence studies demonstrate that the light is linearly polarized p ... [J. Appl. Phys. 101, 053530 (2007)] published Thu Mar 15, 2007.
Inverse magnetocaloric effect in ferromagnetic Ni[sub 50]Mn[sub 37 + x]Sb[sub 13 - x] Heusler alloys
Mahmud Khan, Naushad Ali, and Shane Stadler
A study of the magnetocaloric effect (MCE) in the ferromagnetic Heusler alloys Ni[sub 50]Mn[sub 37+x]Sb[sub 13x] (x=0,0.5,1) has been carried out through magnetization measurements. An inverse magnetocaloric effect was observed in the vicinity of the first order martensitic transition. A maximum pos ... [J. Appl. Phys. 101, 053919 (2007)] published Thu Mar 15, 2007.
Transport phenomena during direct metal deposition
X. He and J. Mazumder
The evolution of temperature and velocity fields during direct metal deposition with coaxial powder injection was simulated using a self-consistent three-dimensional model based on the solution of the equations of mass, momentum, energy conservation, and solute transport in the liquid pool. The basi ... [J. Appl. Phys. 101, 053113 (2007)] published Thu Mar 15, 2007.
Magnetic, electrical, and microstructural characterization of ZnO thin films codoped with Co and Cu
D. Chakraborti, S. Ramachandran, G. Trichy, J. Narayan, and J. T. Prater
Here we report on systematic studies of the epitaxial growth and properties of Co and Cu codoped ZnO thin films deposited onto sapphire c-plane single crystals using pulsed-laser deposition. The films display ferromagnetic behavior at room temperature. Detailed atomic scale characterization rules ou ... [J. Appl. Phys. 101, 053918 (2007)] published Thu Mar 15, 2007.
Intrinsic photoluminescence of M-plane GaN films on LiAlO[sub 2] substrates
Carlos Rivera, Pranob Misra, Jose Luis Pau, Elias Munoz, Oliver Brandt et al.
Polarized photoluminescence spectra of M-plane GaN films grown on LiAlO[sub 2] substrates demonstrate the existence of a large polarization anisotropy in the near-band-gap excitonic transitions, which is consistent with the reduction of the in-plane crystal symmetry and the anisotropic strain genera ... [J. Appl. Phys. 101, 053527 (2007)] published Thu Mar 15, 2007.
Influence of nonstoichiometry on ferroelectric phase transition in BaTiO[sub 3]
Soonil Lee, Zi-Kui Liu, Myong-Ho Kim, and Clive A. Randall
The ferroelectric phase transition behavior in equilibrated nonstoichiometric BaTiO[sub 3] powder samples was characterized by a differential scanning calorimeter. The transition temperature (T[sub C]) and enthalpy of transition (DeltaH[sub T[sub C]]) between the paraelectric and ferroelectric phas ... [J. Appl. Phys. 101, 054119 (2007)] published Thu Mar 15, 2007.
Heat treatment of metal-capped SiO[sub 2] films containing Si nanocrystals
J. Skov Jensen, D. A. Buttenschon, T. P. Leervad Pedersen, J. Chevallier, B. Bech Nielsen et al.
SiO[sub 2] films containing Si nanocrystals and capped with different metal layers (Al, Pd, and Pt) were annealed in a gas containing hydrogen and subsequently studied by photoluminescence (PL). All metal layers were found to greatly increase the photoluminescence from the Si nanocrystals. However, ... [J. Appl. Phys. 101, 056108 (2007)] published Thu Mar 15, 2007.
Thermionic power generation at high temperatures using SiGe/Si superlattices
Daryoosh Vashaee and Ali Shakouri
Recent studies have predicted that heterostructure superlattices can enhance the effective thermoelectric power factor significantly through selective emission of hot carriers via thermionic emission. Here, we study the potential of SiGe/Si superlattices for power generation at high temperatures. A ... [J. Appl. Phys. 101, 053719 (2007)] published Thu Mar 15, 2007.
Tunable thin film polarizer for the vacuum ultraviolet and soft x-ray spectral regions
Minghong Yang, Christoph Cobet, and Norbert Esser
A low pass polarizer that suppresses higher-order diffraction light from vacuum ultraviolet and soft x-ray monochromators is presented in this paper. This vacuum ultraviolet and soft x-ray polarizer is based on a concept of sandwiched metal-dielectric-metal triple reflection configuration. By approp ... [J. Appl. Phys. 101, 053114 (2007)] published Thu Mar 15, 2007.
Local viscosity measurements using oscillating magnetic holes
Eldrid Svsand, Arne T. Skjeltorp, Jorgen Akselvoll, and Geir Helgesen
Many complex fluids are only available in tiny quantities or used in confined regions. The task of measuring their rheological properties is then a challenge. Here we present a method showing how the viscosity of very small volumes of ferrofluid may be measured using immersed nonmagnetic spherical m ... [J. Appl. Phys. 101, 054910 (2007)] published Thu Mar 15, 2007.
Behavior of bending motion of polyurethane film with carbon nanofiber as electrode
Toshihiro Hirai, Mohammad Hamidal Islam, Midori Takasaki, and Masashi Watanabe
The behavior of bending motion by an electric field for a polyurethane elastomer (PUE) film for which vapor grown carbon fiber (VGCF) was used as an electrode was examined. When the electric field was applied to the PUE film with the VGCF electrode, it bent towards the cathode side. In the case wher ... [J. Appl. Phys. 101, 053533 (2007)] published Thu Mar 15, 2007.
Structural and dielectric properties of Ta-modified Pb(Sc[sub 0.5]Nb[sub 0.5])O[sub 3] ceramics
Margarita Correa, R. N. P. Choudhary, and R. S. Katiyar
The polycrystalline (with nanosized particles) samples of Pb(Sc[sub 0.5]Nb[sub (1x)/2]Ta[sub x/2])O[sub 3] (PSNT) (x=0, 0.3, 0.5, 0.7, and 1) were prepared using mechanical activation system and the mixed oxide routes. The compounds were found in rhombohedral structure with the presence of a small a ... [J. Appl. Phys. 101, 054116 (2007)] published Thu Mar 15, 2007.
Deformation and molecular chain evolution of poly(vinylidene fluoride-trifluoroethylene) copolymer films under combined electrical and mechanical loads
F. Fang, W. Yang, M. Z. Zhang, and F. C. Zhang
Deformation and molecular chain evolution under combined electrical and mechanical loads are characterized for poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] copolymer films with 55 and 68 mol % VDF content [termed P(VDF-TrFE) 55/45 and P(VDF-TrFE) 68/32, respectively]. In both copolymer ... [J. Appl. Phys. 101, 053531 (2007)] published Thu Mar 15, 2007.
Dielectric behaviors of Pb(Fe[sub 2/3]W[sub 1/3])-PbTiO[sub 3] relaxors: Models comparison and numerical calculations
Cheng-Shong Hong, Sheng-Yuan Chu, Wen-Chang Su, Ren-Chuan Chang, Hsiau-Hsian Nien et al.
Regarding the dielectric characteristics of the diffusion phase transition (DPT) in ferroelectric relaxor materials, several researchers have provided similar but different laws to explain these phenomenon. These laws, presented by Burfoot et al. and Eiras et al., have been proven to provide a bette ... [J. Appl. Phys. 101, 054120 (2007)] published Thu Mar 15, 2007.
Scattering loss and effective index step of asymmetric cladding surface-etched distributed Bragg reflector lasers at 850 nm
R. K. Price, V. C. Elarde, and J. J. Coleman
The reflectivity of surface-etched distributed Bragg reflector (DBR) laser gratings, suitable for incorporation in photonic integrated circuits, is determined from a series of samples having varied grating etch depths. The effective index step and DBR scattering loss are used to characterize the rel ... [J. Appl. Phys. 101, 053116 (2007)] published Thu Mar 15, 2007.
Three-dimensional particle-in-cell simulations of 300 GHz reflex klystrons
S. G. Jeon, Y. S. Jin, J. I. Kim, G. J. Kim, and C. H. Shon
Three-dimensional (3D) particle-in-cell simulations of 300 GHz reflex klystrons are presented. 300 GHz electromagnetic wave generation in a resonant cavity is analyzed by using a 3D simulation model in which all the geometric parameters (such as the grid thickness, repeller shape, beam radius, etc ... [J. Appl. Phys. 101, 054519 (2007)] published Thu Mar 15, 2007.
A high accuracy technique to measure the electrical conductivity of liquids using small test samples
Jianping Wu and J. P. W. Stark
A large quantity of a sample is usually required in electrical conductivity measurements of fluids. If precise electrical conductivity measurements are to be performed while using small test samples, it is necessary to study the effects of both fringe electric fields and interfacial properties. Thes ... [J. Appl. Phys. 101, 054520 (2007)] published Thu Mar 15, 2007.
Magnetic and magnetocaloric properties of Cu-substituted La[sub 1 - x]Pb[sub x]MnO[sub 3] (x ~ 0.14) single crystals
B. C. Zhao, Y. P. Sun, X. B. Zhu, and W. H. Song
Structural, magnetic, and magnetocaloric properties in perovskite manganites La[sub 1x]Pb[sub x]Mn[sub 1yz]Cu[sub y]O[sub 3] (x~0.14, y=0, 0.01, 0.02, z=0.02, 0.08, 0.11) single crystals have been investigated. The Curie temperature T[sub C] decreases monotonously with increasing Cu-doping concentra ... [J. Appl. Phys. 101, 053920 (2007)] published Thu Mar 15, 2007.
Relaxation property of the magnetic-fluid-based fiber-optic evanescent field modulator
Shengli Pu, Xianfeng Chen, Ziyun Di, and Yuxing Xia
The details about the modulation property of the magnetic-fluid-based fiber-optic evanescent field modulator are studied in this article. Experiments show that it needs some time for the outgoing light from the modulator to reach the final steady value when the external magnetic field is turned on o ... [J. Appl. Phys. 101, 053532 (2007)] published Thu Mar 15, 2007.
Shock wave compression of the ferroelectric ceramic Pb[sub 0.99](Zr[sub 0.95]Ti[sub 0.05])[sub 0.98]Nb[sub 0.02]O[sub 3]: Microstructural effects
Robert E. Setchell
Shock wave compression of poled Pb[sub 0.99](Zr[sub 0.95]Ti[sub 0.05])[sub 0.98]Nb[sub 0.02]O[sub 3] results in rapid depoling and release of bound charge. Different porous microstructures can be produced in the material by adding different types and amounts of organic pore formers prior to bisque f ... [J. Appl. Phys. 101, 053525 (2007)] published Thu Mar 15, 2007.
Controlled catalytic growth and characterization of zinc oxide nanopillars on a-plane sapphire
A. Reiser, A. Ladenburger, G. M. Prinz, M. Schirra, M. Feneberg et al.
Using the vapor-liquid-solid (VLS) technique, we have grown well-aligned nanopillars on [11[overline 2]0]-sapphire (a-plane) substrates at atmospheric pressure in a horizontal tube furnace employing gold catalyst seeds of different sizes and densities. It was the aim of the present work to find expe ... [J. Appl. Phys. 101, 054319 (2007)] published Thu Mar 15, 2007.
Growth, microstructure, and ferroelectric properties of Pb(Zr[sub 0.4]Ti[sub 0.6])O[sub 3]/PbZrO[sub 3] superlattices prepared on SrTiO[sub 3] (100) substrates by pulsed laser deposition
Dinghua Bao, Roland Scholz, Marin Alexe, and Dietrich Hesse
Artificially designed Pb(Zr,Ti)O[sub 3] (PZT)/PbZrO[sub 3] (PZ) superlattices were grown on (100)-oriented SrTiO[sub 3] (STO) substrates with and without SrRuO[sub 3] bottom electrodes by pulsed laser deposition. Their microstructure was characterized using x-ray diffraction and transmission electro ... [J. Appl. Phys. 101, 054118 (2007)] published Thu Mar 15, 2007.
Linear theory of the electron beam-wave-plasma interactions in a magnetized plasma waveguide
Shenggang Liu, Yanyu Wei, XueSong Yuan, and Yang Yan
The theoretical study on the electron beam-wave interactions in a plasma waveguide immersed in a finite magnetic field is given in the article, in which both the plasma and the electron beam are considered as special media. Making use of the constitutive transformation and the Lorentz transformation ... [J. Appl. Phys. 101, 053309 (2007)] published Thu Mar 15, 2007.
High-mobility and air-stable organic thin-film transistors with highly ordered semiconducting polymer films
Tokiyoshi Umeda, Shizuo Tokito, and Daisuke Kumaki
We report on high crystalline thin films of liquid-crystalline polythiophene derivative, poly(2,5-bis(3-hexadecylthiophene-2-yl)thieno[3,2-b]thiophene) (PB16TTT) that exhibit terrace structures and molecular steps of its polymer chains by annealing in its liquid-crystalline phase. The crystallinity ... [J. Appl. Phys. 101, 054517 (2007)] published Thu Mar 15, 2007.
Ultraviolet emission and Fano resonance in doped nano-alumina
Bin Li, Samuel L. Oliveira, Stephen C. Rand, Jose A. Azurdia, Tom R. Hinklin et al.
Emission properties of Al[sub 2]O[sub 3] nanopowders, synthesized by flame spray pyrolysis with Mg, Cr, and Sc dopants, are investigated, principally in the protein lysing range of 250290 nm (UV-C band). As expected, point defect densities depend on crystal phase and irradiation history and strongl ... [J. Appl. Phys. 101, 053534 (2007)] published Thu Mar 15, 2007.
Influence of electron beam exposure on crystallization of phase-change materials
Ramanathaswamy Pandian, Bart J. Kooi, Jeff Th. M. De Hosson, and Andrew Pauza
Isothermal crystallization of amorphous Sb[sub x]Te films capped with ZnS-SiO[sub 2] or GeCrN layers was performed using in situ heating within a transmission electron microscope. The effect of the electron beam of the microscope on the crystallization process was investigated. It was found that ele ... [J. Appl. Phys. 101, 053529 (2007)] published Thu Mar 15, 2007.
Effects of the MnO additives on the properties of Pb(Fe[sub 2/3]W[sub 1/3])--PbTiO[sub 3] relaxors: Comparison of empirical law and experimental results
Cheng-Shong Hong, Sheng-Yuan Chu, Wen-Chang Su, Ren-Chuan Chang, Hsiau-Hsian Nien et al.
In this paper, pure and 0.15 wt %MnO additives of (1x)Pb(Fe[sub 2/3]W[sub 1/3])O[sub 3]xPbTiO[sub 3] [(1x)PFW[sub x]PT] with x=0.1, 0.2, 0.3, and 0.4 were synthesized by the conventional solid state reaction method. The dielectric diffusion properties were investigated with the empirical law. The ... [J. Appl. Phys. 101, 054117 (2007)] published Thu Mar 15, 2007.
Temporally evolved recoil pressure driven melt infiltration during laser surface modifications of porous alumina ceramic
Sandip P. Harimkar, Anoop N. Samant, and Narendra B. Dahotre
Laser surface modification of porous alumina ceramic with a high power laser is associated with a series of physical processes such as heating, melting, and evaporation of material. Above certain threshold laser intensity (~10[sup 10] W/m[sup 2]), rapid evaporation at melt surface generates strong ... [J. Appl. Phys. 101, 054911 (2007)] published Thu Mar 15, 2007.
Compensation mechanism in high purity semi-insulating 4H-SiC
W. C. Mitchel, William D. Mitchell, H. E. Smith, G. Landis, S. R. Smith et al.
A study of deep levels in high purity semi-insulating 4H-SiC has been made using temperature dependent Hall effect (TDH), thermal and optical admittance spectroscopies, and secondary ion mass spectrometry (SIMS). Thermal activation energies from TDH varied from a low of 0.55 eV to a high of 1.65 e ... [J. Appl. Phys. 101, 053716 (2007)] published Thu Mar 15, 2007.
Microcrystalline, nanocrystalline, and ultrananocrystalline diamond chemical vapor deposition: Experiment and modeling of the factors controlling growth rate, nucleation, and crystal size
P. W. May, M. N. R. Ashfold, and Yu. A. Mankelevich
Ar/CH[sub 4]/H[sub 2] gas mixtures have been used to deposit microcrystalline diamond, nanocrystalline diamond, and ultrananocrystalline diamond films using hot filament chemical vapor deposition. A three-dimensional computer model was used to calculate the gas phase composition for the experimental ... [J. Appl. Phys. 101, 053115 (2007)] published Thu Mar 15, 2007.
Effect of magnetic field on dislocation-oxygen impurity interaction in silicon
I. Yonenaga and K. Takahashi
Dislocation-oxygen impurity interaction in Czochralski-grown silicon crystals was influenced by treatments at temperature of 650 degrees C under a magnetic field up to 8 T. It was found that the critical stress for dislocation generation from a surface scratch varies with an intensity of the appl ... [J. Appl. Phys. 101, 053528 (2007)] published Thu Mar 15, 2007.
Thermal conductivity modeling of compacted nanowire composites
Weixue Tian and Ronggui Yang
Nanocomposites may realize a similar thermal conductivity reduction and thermoelectric efficiency enhancement observed in superlattices and thus provide a pathway to scale up the benefits of the nanoscale effects to thermoelectric materials in bulk form. If there are two species, nanocomposites can ... [J. Appl. Phys. 101, 054320 (2007)] published Thu Mar 15, 2007.
Synthesis of monocrystal aluminum nitride nanowires at low temperature
Huimin Lv, Guangde Chen, Honggang Ye, and Guojun Yan
Hexagonal monocrystal aluminum nitride (h-AlN) nanowires are synthesized through the direct reaction of AlCl[sub 3] with NaN[sub 3] in a nonsolvent system at low temperatures. The h-AlN nanowires are characterized by the high-resolution transmission electron microscope, electron diffraction, x-ray d ... [J. Appl. Phys. 101, 053526 (2007)] published Thu Mar 15, 2007.
Electrical and structural characterization of Mg-doped p-type Al[sub 0.69]Ga[sub 0.31]N films on SiC substrate
Arpan Chakraborty, Craig G. Moe, Yuan Wu, Tom Mates, Stacia Keller et al.
We report on the electrical and structural characterization of Mg-doped Al-rich p-type Al[sub 0.69]Ga[sub 0.31]N alloys on SiC substrate grown by metal organic chemical vapor deposition. The impact of growth conditions and dopant activation annealing conditions on the electrical conductivity was inv ... [J. Appl. Phys. 101, 053717 (2007)] published Thu Mar 15, 2007.
Interpretation of distributed-feedback-laser spectrum using reflection properties of Bloch waves
A. V. Maslov and C. Z. Ning
We demonstrate that the phase and amplitude of the reflection coefficient for Bloch waves can be useful tools in understanding and predicting the spectral characteristics of distributed-feedback lasers. We further apply the Bloch wave formalism for engineering the asymmetry of the spectral response ... [J. Appl. Phys. 101, 053117 (2007)] published Thu Mar 15, 2007.
Relaxor-like behavior of lead-free Sr[sub 2]LaTi[sub 2]Nb[sub 3]O[sub 15] ceramics with tetragonal tungsten bronze structure
V. Bovtun, S. Kamba, S. Veljko, D. Nuzhnyy, K. Knižek et al.
Lead-free tetragonal tungsten bronze Sr[sub 2]LaTi[sub 2]Nb[sub 3]O[sub 15] ceramics were prepared and its crystal structure determined. Dielectric response of Sr[sub 2]LaTi[sub 2]Nb[sub 3]O[sub 15] was investigated in a broad frequency (100 Hz90 THz) and temperature range. The observed relaxor-like ... [J. Appl. Phys. 101, 054115 (2007)] published Thu Mar 15, 2007.
Thick film polymer-ceramic composites for pyroelectric applications
M. Dietze, J. Krause, C.-H. Solterbeck, and M. Es-Souni
Thick films of 0-3 composites of lead-zirconate-titanate ceramic and polyvinylidene-trifluorethylene copolymer have been produced by spin coating on gold-coated silicon wafers. The dielectric properties were investigated as a function of ceramic volume fraction and temperature. Pyroelectric measurem ... [J. Appl. Phys. 101, 054113 (2007)] published Wed Mar 14, 2007.
Stress-induced anisotropy of graphitelike amorphous carbon
Stefan Zollner, Wentao Qin, Richard B. Gregory, N. V. Edwards, Kurt Junker et al.
Ellipsometry spectra of graphitelike amorphous carbon films on Si reveal a strong anisotropy of the optical constants in the 0.79.5 eV photon-energy range. The films are optically uniaxial, with the optical axis oriented normal to the surface. This birefringence can be explained by ordering of the ... [J. Appl. Phys. 101, 053522 (2007)] published Wed Mar 14, 2007.
Lateral field excitation of thickness shear mode waves in a thin film ZnO solidly mounted resonator
Christopher D. Corso, Anthony Dickherber, and William D. Hunt
In recent years, interest in the development of highly sensitive acoustic wave devices as biosensor platforms has grown. A considerable amount of research has been conducted on AT-cut quartz resonators both in thickness excitation and in lateral excitation configurations. In this report, we demonstr ... [J. Appl. Phys. 101, 054514 (2007)] published Wed Mar 14, 2007.
Rotator and extender ferroelectrics: Importance of the shear coefficient to the piezoelectric properties of domain-engineered crystals and ceramics
Matthew Davis, Marko Budimir, Dragan Damjanovic, and Nava Setter
The importance of a high shear coefficient d[sub 15] (or d[sub 24]) to the piezoelectric properties of domain-engineered and polycrystalline ferroelectrics is discussed. The extent of polarization rotation, as a mechanism of piezoelectric response, is directly correlated to the shear coefficient. Th ... [J. Appl. Phys. 101, 054112 (2007)] published Wed Mar 14, 2007.
Judd-Ofelt analysis of spectroscopic property of Er[sup 3+] in congruent and near-stoichiometric Zn/Er-codoped LiNbO[sub 3] crystals
De-Long Zhang, Ping-Rang Hua, Yu-Heng Xu, and E. Y. B. Pun
Congruent LiNbO[sub 3] crystals doped with 5.5/1, 6/0.15, and 7/0.8 mol %/mol % of Zn/Er were thermally treated at 1120 degrees C over 101 h using vapor transport equilibration (VTE) technique. Unpolarized visible and infrared absorption spectra of the VTE-treated and corresponding as-grown cr ... [J. Appl. Phys. 101, 053523 (2007)] published Wed Mar 14, 2007.
GaAs whiskers grown by metal-organic vapor-phase epitaxy using Fe nanoparticles
Ingo Regolin, Victor Khorenko, Werner Prost, Franz J. Tegude, Daniela Sudfeld et al.
GaAs nanowhiskers were grown by metal-organic vapor-phase epitaxy on (111)B GaAs substrates. The diameter of the nanowhiskers was defined by monodisperse Fe nanoparticles deposited on the GaAs substrate from the vapor phase. The growth temperature of the whiskers was investigated from 480 to 520 ... [J. Appl. Phys. 101, 054318 (2007)] published Wed Mar 14, 2007.
Spin noise fluctuations from paramagnetic molecular adsorbates on surfaces
Paolo Messina, Matteo Mannini, Andrea Caneschi, Dante Gatteschi, Lorenzo Sorace et al.
The measurement of spin noise in nuclei was demonstrated on bulk samples more than two decades ago. An ensemble of spins can produce a coherent signal at the Larmor frequency of a static magnetic field, known as spin noise, an effect due to the statistical polarization of small ensembles. The diffic ... [J. Appl. Phys. 101, 053916 (2007)] published Wed Mar 14, 2007.
Surface nucleation of the (111) plane of excimer laser annealed Si on SiO[sub 2] substrates: A molecular dynamics study
Byoung Min Lee, Takahide Kuranaga, Shinji Munetoh, and Teruaki Motooka
We have investigated the nucleation and crystallization processes of molten silicon (Si) on SiO[sub 2] substrates by performing molecular dynamics (MD) simulations based on the modified Tersoff potential parameters. A heat flow that leads to a steady fall of the local temperature in the molten Si is ... [J. Appl. Phys. 101, 054316 (2007)] published Wed Mar 14, 2007.
Nature of the cubic to rhombohedral structural transformation in (AgSbTe[sub 2])[sub 15](GeTe)[sub 85] thermoelectric material
B. A. Cook, M. J. Kramer, X. Wei, J. L. Harringa, and E. M. Levin
The existence of a large thermoelectric figure of merit in (AgSbTe[sub 2])[sub 15](GeTe)[sub 85] has been known for many years. However, the nature of the crystallographic transformation in these materials from a high-temperature cubic to a low-temperature rhombohedral polymorph and its effect on el ... [J. Appl. Phys. 101, 053715 (2007)] published Wed Mar 14, 2007.
Impact of the etching gas on vertically oriented single wall and few walled carbon nanotubes by plasma enhanced chemical vapor deposition
A. Gohier, T. M. Minea, M. A. Djouadi, and A. Granier
Vertically oriented single wall nanotubes (SWNTs) and few walled nanotubes (FWNTs) have been grown by electronic cyclotron resonance plasma enhanced chemical vapor deposition (PECVD) on silica flat substrates. The impact of the plasma parameters on SWNT and FWNT growth has been investigated using tw ... [J. Appl. Phys. 101, 054317 (2007)] published Wed Mar 14, 2007.
Temperature dependence of the yttria-stabilized zirconia Raman spectrum
Vanni Lughi and David R. Clarke
The Raman spectrum of 5 wt % yttria-stabilized tetragonal zirconia from 25 to 1250 degrees C is reported. All six Raman bands broaden and shift toward lower energy with increasing temperature. The shift associated with thermally induced volume changes is shown to be the main contribution for a ... [J. Appl. Phys. 101, 053524 (2007)] published Wed Mar 14, 2007.
Ferroelectrets with improved thermal stability made from fused fluorocarbon layers
X. Zhang, J. Hillenbrand, and G. M. Sessler
Several layers of polytetrafluoroethylene and fluoroethylenepropylene films are fused such that small interfacial gas voids are formed between the layers. After proper charging and annealing, the fused multilayer films show large and thermally stable quasistatic piezoelectric d[sub 33] coefficients ... [J. Appl. Phys. 101, 054114 (2007)] published Wed Mar 14, 2007.
Electric-field-dependent charge transport in organic thin-film transistors
Liang Wang, Daniel Fine, Debarshi Basu, and Ananth Dodabalapur
This article reports the experimental study of the electric-field-dependent charge transport mechanisms in polycrystalline organic thin-film field-effect transistors. This work represents the quantitative measurement of the temperature and electric-field dependences of the mobility in organic thin-f ... [J. Appl. Phys. 101, 054515 (2007)] published Wed Mar 14, 2007.
CoFe-based amorphous alloy with high relaxation frequency
I. Betancourt and F. Vazquez
Amorphous Co[sub 43]Fe[sub 20]B[sub 31.5]Ta[sub 5.5] ribbons prepared by melt-spinning technique, showed a relaxation frequency f[sub x] of 3 MHz, higher than any other known amorphous alloy. Additional complex permeability measurements reflected the reversible bulging of domain walls as the active ... [J. Appl. Phys. 101, 053917 (2007)] published Wed Mar 14, 2007.
Effects of a-Si:H layer thicknesses on the performance of a-Si:H/c-Si heterojunction solar cells
Hiroyuki Fujiwara and Michio Kondo
We have fabricated hydrogenated amorphous silicon (a-Si:H)/crystalline silicon (c-Si) heterojunction solar cells with different a-Si:H layer thicknesses, in order to determine effects of a-Si:H layer thicknesses on the performance of a-Si:H/c-Si solar cells. The thicknesses of a-Si:H p-i layers form ... [J. Appl. Phys. 101, 054516 (2007)] published Wed Mar 14, 2007.
Low dimensional intermediate valence fluctuation in single crystalline YbB[sub 4]
J. Y. Kim, B. K. Cho, H. J. Lee, and H.-C. Kim
Temperature-dependent magnetization M(T), resistivity rho(T), and specific heat C[sub p](T) were measured for single crystalline YbB[sub 4]. M(T) showed a large anisotropy, that is M[sub ||](T)>M[sub [perpendicular]](T), for fields parallel and perpendicular, respectively, to the c axis. While M[sub ... [J. Appl. Phys. 101, 09D501 (2007)] published Wed Mar 14, 2007.
High-temperature perovskite relaxor ferroelectrics: A comparative study
C. J. Stringer, T. R. Shrout, and C. A. Randall
The recent discovery of high-temperature piezoelectric ceramics based on Bi(Me[sup [prime]]Me[sup [double-prime]])O[sub 3]-PbTiO[sub 3] solutions have also permitted the development of high-temperature relaxor ferroelectrics with ternary solid solutions. One of the high-temperature compositions base ... [J. Appl. Phys. 101, 054107 (2007)] published Tue Mar 13, 2007.
N[sub 2] adsorption study on quartz, silver, and carbon nanotube by inductive pulse quartz crystal microbalance
Jang-ik Park, Insuk Yu, and Yongho Seo
We utilize an inductive pulse quartz crystal microbalance method to study N[sub 2] adsorption on quartz, silver, and a single wall carbon nanotube at 77 K. This method is based on radio frequency electric pulse excitation and ring-down signal measurements of quartz crystal resonators located in an i ... [J. Appl. Phys. 101, 053521 (2007)] published Tue Mar 13, 2007.
Effect of polarization and self-energy on the ground donor state in the presence of conduction band nonparabolicity in GaAs--(Al,Ga)As spherical quantum dot
M. K. Bose, K. Midya, and C. Bose
Based on the variational technique, the binding energy associated with the ground donor state in the presence of conduction band nonparabolicity, polarization charge, and self-energy is estimated for a finite-barrier quantum dot, with a hydrogenic impurity located at its center. The overall effect o ... [J. Appl. Phys. 101, 054315 (2007)] published Tue Mar 13, 2007.
Irradiation effects on domain dynamics in ferroelectric glycine phosphite
S. Vanishri, J. N. Babu Reddy, and H. L. Bhat
The effect of x-ray irradiation on polarization switching properties of a glycine phosphite (GPI) single crystal is investigated using the Merz technique. GPI undergoes a paraelectric to ferroelectric phase transition at 224.7 K. Switching studies were performed in the temperature range of 173221 K ... [J. Appl. Phys. 101, 054106 (2007)] published Tue Mar 13, 2007.
Enhancement of electron-longitudinal optical phonon coupling in highly strained InGaN/GaN quantum well structures
Dong Chen, Yi Luo, Lai Wang, Hongtao Li, Guangyi Xi et al.
An anomalously strong phonon replica is observed in the photoluminescence (PL) spectra of In[sub 0.23]Ga[sub 0.77]N/GaN multiple quantum well (MQW) samples at 10 K. The Huang-Rhys factor for the two-well sample reaches 0.95, in contrast to the value of 0.45 for the five-well sample obtained with the ... [J. Appl. Phys. 101, 053712 (2007)] published Tue Mar 13, 2007.
Anisotropy of ferroelectric and piezoelectric properties of Bi[sub 3.15]Pr[sub 0.85]Ti[sub 3]O[sub 12] thin films on Pt(100)/Ti/SiO[sub 2]/Si substrates
G. D. Hu, S. H. Fan, and X. Cheng
Bi[sub 3.15]Pr[sub 0.85]Ti[sub 3]O[sub 12] (BPT) thin films with (100) (alpha[sub (100)]=89.1%), (117) (alpha[sub (117)]=83.2%), and (001) (alpha[sub (001)]=99.7%) orientations and a c-axis-oriented (alpha[sub (001)]=99.9%) Bi[sub 4]Ti[sub 3]O[sub 12] (BT) film were deposited on Pt(100)/TiO[sub 2]/S ... [J. Appl. Phys. 101, 054111 (2007)] published Tue Mar 13, 2007.
Effects of thermal and electrical histories on hard piezoelectrics: A comparison of internal dipolar fields and external dc bias
Yongkang Gao, Kenji Uchino, and Dwight Viehland
Rare earth modified Pb(Zr,Ti)O[sub 3]Pb(Sb,Mn)O[sub 3] piezoelectric ceramics have been studied for various thermal and electrical histories. In both freshly poled and unpoled conditions, thermal quenching was found to increase the remnant polarization (P[sub r]) and induced strain of hard piezoelec ... [J. Appl. Phys. 101, 054109 (2007)] published Tue Mar 13, 2007.
Thin film solid-state reactions forming carbides as contact materials for carbon-containing semiconductors
W. P. Leroy, C. Detavernier, R. L. Van Meirhaeghe, and C. Lavoie
Metal carbides are good candidates to contact carbon-based semiconductors (SiC, diamond, and carbon nanotubes). Here, we report on an in situ study of carbide formation during the solid-state reaction between thin films. The solid-state reaction was examined between 11 transition metals (W, Mo, Fe, ... [J. Appl. Phys. 101, 053714 (2007)] published Tue Mar 13, 2007.
Analytical saturated domain orientation textures and electromechanical properties of ferroelectric ceramics due to electric/mechanical poling
F. X. Li and R. K. N. D. Rajapakse
Saturated domain orientation textures of three types of pseudocubic (tetragonal, rhombohedral, and orthorhombic) ferroelectric ceramics after complete electric and uniaxial tension (compression) poling is studied analytically in this paper. A one-dimensional orientation distribution function (ODF) o ... [J. Appl. Phys. 101, 054110 (2007)] published Tue Mar 13, 2007.
Thermoelectric properties of hot-pressed skutterudite CoSb[sub 3]
Zeming He, Christian Stiewe, Dieter Platzek, Gabriele Karpinski, Eckhard Muller et al.
In the present work, skutterudite CoSb[sub 3] were fabricated by hot pressing at different sintering temperatures under vacuum and argon. For the prepared compacts, the phase, the microstructure, and the temperature dependent thermoelectric properties were characterized. The correlation of the mater ... [J. Appl. Phys. 101, 053713 (2007)] published Tue Mar 13, 2007.
Depolarization of a piezoelectric film under an alternating current field
K. W. Kwok, M. K. Cheung, H. L. W. Chan, and C. L. Choy
In this article, we demonstrate that a sol-gel-derived niobium-doped lead zirconate titanate film can be depolarized by the application of alternating current (ac) fields of diminishing amplitude and we explain the phenomenon based on the concept of the Preisach model. The amplitude of the ac fields ... [J. Appl. Phys. 101, 054108 (2007)] published Tue Mar 13, 2007.
Crackling noise peaks as signature of avalanche correlation
Edvige Celasco, Marcello Celasco, and Roberto Eggenhoffner
Until now, all existing theories failed to explain peaks in the power noise spectra. Here we focus on the role of correlation among avalanches as the main source of the noise peaks observed. The present theory is based on first principles statistics of elementary events clustered in time-amplitude c ... [J. Appl. Phys. 101, 054908 (2007)] published Tue Mar 13, 2007.
Coupling of spin-transfer torque to microwave magnetic field: A micromagnetic modal analysis
L. Torres, L. Lopez-Diaz, E. Martinez, G. Finocchio, M. Carpentieri et al.
Micromagnetic computational spectral mapping technique is applied to analyze the magnetic oscillation modes excited by either a microwave circularly polarized magnetic field or a spin polarized current flowing through Permalloy (Py) spin valves. A complete study has been carried out on multilayers P ... [J. Appl. Phys. 101, 053914 (2007)] published Tue Mar 13, 2007.
Hysteresis scaling of uniaxially anisotropic Heisenberg model
Y. B. Guo, X. Chen, and J.-M. Liu
We simulate by the Monte Carlo method the dynamic hysteresis and hysteresis scaling of two-dimensional uniaxially anisotropic Heisenberg model submitted to a time-oscillating magnetic field h of frequency f and amplitude h[sub 0]. It is revealed that the hysteresis area as a function of f and h[sub ... [J. Appl. Phys. 101, 053915 (2007)] published Tue Mar 13, 2007.
A computationally efficient model of convective heat transfer and solidification characteristics during keyhole mode laser welding
R. Rai, G. G. Roy, and T. DebRoy
Computationally efficient heat transfer models of keyhole mode laser welding ignore fluid flow in the gas, liquid, and the two phase solid-liquid regions. These models cannot be applied to high Peclet number systems where convective heat transfer affects weld pool geometry, cooling rate, and other w ... [J. Appl. Phys. 101, 054909 (2007)] published Tue Mar 13, 2007.
The effect of Si doping on the electrical properties of B[sub 12]As[sub 2] thin films on (0001) 6H-SiC substrates
Zhou Xu, J. H. Edgar, D. C. Look, S. Baumann, R. J. Bleiler et al.
The ability to control the resistivity of the wide band gap semiconductor B[sub 12]As[sub 2] by doping with silicon was verified. The electrical properties of nominally undoped and Si-doped rhombohedral B[sub 12]As[sub 2] thin films on semi-insulating 6H-SiC (0001) substrates prepared by chemical va ... [J. Appl. Phys. 101, 053710 (2007)] published Mon Mar 12, 2007.
A molecular dynamics model for the interaction of energetic ions with SiOCH low-kappa dielectric
V. V. Smirnov, A. V. Stengach, K. G. Gaynullin, V. A. Pavlovsky, S. Rauf et al.
A molecular dynamics model is used to investigate the interaction of energetic ions with fluorocarbon passivated Si, O, C, and H (SiOCH) based low-kappa dielectrics. The model includes a set of interatomic potentials required for the SiOCHCF[sub x] interaction system, where the two- and three-body p ... [J. Appl. Phys. 101, 053307 (2007)] published Mon Mar 12, 2007.
Bragg-case K-vector[sub g] and K-vector[sub 0] beam double-crystal synchrotron studies of growth sectors and dislocations in synthetic diamonds
W. K. Wierzchowski and Moreton Moore
A slab of synthetic diamond 4 x 4 x 1.5 mm[sup 3] has been studied in Bragg-case, simultaneously in reflected and transmitted beams, using a double-crystal topographic method with a synchrotron source of x-rays. The examined diamond had been grown by the reconstitution method and was of a cuboctahed ... [J. Appl. Phys. 101, 053518 (2007)] published Mon Mar 12, 2007.
Observation of room temperature magnetoelectric coupling in Pb[sub 1 - x]Ba[sub x](Fe[sub 0.5]Ti[sub 0.5])O[sub 3] system
Manoj Kumar and K. L. Yadav
Magnetoelectric coupling at room temperature in Pb[sub 1x]Ba[sub x](Fe[sub 0.5]Ti[sub 0.5])O[sub 3] (x=0.2 and 0.4) ceramics prepared by conventional solid state reaction method was observed. The Ba substitution for Pb reduces the lattice distortion, i.e., c/a ratio, and hence the ferroelectric tran ... [J. Appl. Phys. 101, 054105 (2007)] published Mon Mar 12, 2007.
Elastic anisotropy of an Fe[sub 79]Si[sub 12]B[sub 9] amorphous alloy thin film studied by ultrasound spectroscopy
Ryuichi Tarumi, Akira Shibata, Hirotsugu Ogi, Masahiko Hirao, Kazuki Takashima et al.
A complete set of elastic constants C[sub ij] of an Fe[sub 79]Si[sub 12]B[sub 9] amorphous alloy free standing thin film has been determined by using ultrasound spectroscopy techniques. The out-of-plane shear moduli of C[sub 44] and C[sub 55] are measured by the thickness resonance frequencies and a ... [J. Appl. Phys. 101, 053519 (2007)] published Mon Mar 12, 2007.
Characterization of a low-pressure argon plasma using optical emission spectroscopy and a global model
A. Palmero, E. D. van Hattum, H. Rudolph, and F. H. P. M. Habraken
The excitation mechanisms of the lower lying excited levels in a low-ionized, low-pressure, argon plasma are modeled and studied in order to characterize the plasma through optical emission spectroscopy. It is found that the lower lying excited states of argon play an important role in the excitatio ... [J. Appl. Phys. 101, 053306 (2007)] published Mon Mar 12, 2007.
Properties of nanostructured Ge produced by laser-induced air breakdown processing
A. V. Kabashin, F. Magny, and M. Meunier
Germanium wafers have been modified by a technique of laser-induced air breakdown processing. It has been found that the treatment leads to the formation of porous layers, containing nanoscale holes, and consists of Ge nanocrystals embedded into GeO[sub 2] matrices. They exhibit strong and stable ph ... [J. Appl. Phys. 101, 054311 (2007)] published Mon Mar 12, 2007.
Photoacoustic characterization of carbon nanotube array thermal interfaces
Baratunde A. Cola, Jun Xu, Changrui Cheng, Xianfan Xu, Timothy S. Fisher et al.
This work describes an experimental study of thermal conductance across multiwalled carbon nanotube (CNT) array interfaces, one sided (Si-CNT-Ag) and two sided (Si-CNT-CNT-Cu), using a photoacoustic technique (PA). Well-anchored, dense, and vertically oriented multiwalled CNT arrays have been direct ... [J. Appl. Phys. 101, 054313 (2007)] published Mon Mar 12, 2007.
Exact variational nonlocal stress modeling with asymptotic higher-order strain gradients for nanobeams
C. W. Lim and C. M. Wang
This article presents a complete and asymptotic representation of the one-dimensional nanobeam model with nonlocal stress via an exact variational principle approach. An asymptotic governing differential equation of infinite-order strain gradient model and the corresponding infinite number of bounda ... [J. Appl. Phys. 101, 054312 (2007)] published Mon Mar 12, 2007.
Attenuation of wave in a thin plasma layer by finite-difference time-domain analysis
Minghai Liu, Xiwei Hu, Zhonghe Jiang, Shu Zhang, and Chaohui Lan
The attenuation of the electromagnetic wave in a thin plasma layer at high pressure is investigated with finite-difference time-domain method. The effects of the plasma thickness, plasma density distribution function, collision frequency between electron and neutrals, and the frequency of incident w ... [J. Appl. Phys. 101, 053308 (2007)] published Mon Mar 12, 2007.
Inductive magnetization of low-temperature ordered L1[sub 0]-FePt with CoAg underlayer
Yu-Cheng Lai, Yen-Hwei Chang, Yen-Chia Chen, Chih-hao Liang, Wen-Cheng Chang et al.
The feasibility of controlling film microstructure and nanocomposition of FePt film with various compositions of the CoAg underlayer by ion beam sputtering accompanied by an external magnetic field was performed. The characteristic of phase separation of the CoAg underlayer was employed to induce an ... [J. Appl. Phys. 101, 053913 (2007)] published Mon Mar 12, 2007.
Nanostructuring and thermoelectric properties of bulk skutterudite compound CoSb[sub 3]
J. L. Mi, T. J. Zhu, X. B. Zhao, and J. Ma
Thermoelectric properties of nanostructured skutterudite CoSb[sub 3] have been reported. Nanosized CoSb[sub 3] powders were synthesized through a solvothermal route. The bulk materials with average grain sizes of 250 and 150 nm were prepared by hot pressing and spark plasma sintering from the solvo ... [J. Appl. Phys. 101, 054314 (2007)] published Mon Mar 12, 2007.
Two characteristic photoluminescence states and their metastability in hydrogenated amorphous silicon and its alloys
Hidetoshi Oheda
Photoluminescence (PL) lifetime distributions, G(tau), in hydrogenated amorphous silicon (a-Si:H) and its alloys are studied by frequency resolved spectroscopy. Two lifetime components, which are characterized with respective specific peak lifetimes of about 1 ms and 10 [mu]s, are commonly observe ... [J. Appl. Phys. 101, 053711 (2007)] published Mon Mar 12, 2007.
Mechanism of enhanced adhesion between hydrogenated amorphous carbon films and tungsten preimplanted steel substrates
Ming Xu, Xun Cai, Qiulong Chen, Jun Zhao, and Paul K. Chu
Hydrogenated amorphous carbon (a-C:H) films have good mechanical properties but poor adhesion on substrates such as tool steels thereby limiting their applications. Film adhesion can be improved by conducting tungsten preimplantation into the steel substrates before deposition of the carbon film. Th ... [J. Appl. Phys. 101, 053520 (2007)] published Mon Mar 12, 2007.
Low-loss planar and stripe waveguides in Nd[sup 3+]-doped silicate glass produced by oxygen-ion implantation
Lei Wang, Feng Chen, Xue-Lin Wang, Ke-Ming Wang, Yang Jiao et al.
We report on the fabrication and characterization of low-loss planar and stripe waveguides in a Nd[sup 3+]-doped glass by 6 MeV oxygen-ion implantation at a dose of 1 x 10[sup 15] ions/cm[sup 2]. The dark mode spectroscopy of the planar waveguide was measured using a prism coupling arrangement. Th ... [J. Appl. Phys. 101, 053112 (2007)] published Mon Mar 12, 2007.
Optical spectra and spin Hamiltonian parameters for rhombic Zr[sup 3+] in Y[sub 3]Al[sub 5]O[sub 12]
Wen-Chen Zheng, Wang Fang, and Yang Mei
The four optical spectrum bands (or d-d transitions) and six spin Hamiltonian parameters (g factors g[sub x], g[sub y], g[sub z] and hyperfine structure constants A[sub x], A[sub y], A[sub z]) of the rhombic Zr[sup 3+] (4d[sup 1]) center in Y[sub 3]Al[sub 5]O[sub 12] crystal are calculated from the ... [J. Appl. Phys. 101, 053911 (2007)] published Fri Mar 9, 2007.
Spatially resolved modeling of the combined effect of dislocations and grain boundaries on minority carrier lifetime in multicrystalline silicon
G. Stokkan, S. Riepe, O. Lohne, and W. Warta
A model for the combined effect of dislocations and grain boundaries on minority carrier lifetime has been developed. Lifetime varies with dislocation density, grain boundary misorientation, and the coincidence site lattice (CSL) nature of the boundaries. Minority carrier lifetime was measured with ... [J. Appl. Phys. 101, 053515 (2007)] published Fri Mar 9, 2007.
Morphology of basal plane dislocations in 4H-SiC homoepitaxial layers grown by chemical vapor deposition
X. Zhang, S. Ha, Y. Hanlumnyang, C. H. Chou, V. Rodriguez et al.
The morphology of basal plane dislocations (BPDs) in 4H-SiC homoepitaxial layers has been investigated by plan-view transmission x-ray topography and molten KOH etching. Three types of BPDs are distinguished based on their morphologies. These include interfacial dislocations, curved dislocations, an ... [J. Appl. Phys. 101, 053517 (2007)] published Fri Mar 9, 2007.
Improving the stability of organic light-emitting devices by using a hole-injection-tunable-anode-buffer-layer
Yichun Luo, Hany Aziz, Gu Xu, and Zoran D. Popovic
Introducing a hole-injection-tunable-anode-buffer-layer (HITABL) at the indium tin oxide anode contact of an organic light-emitting device can finely tune hole injection to establish proper charge balance, thus remarkably improves its operational stability. The HITABL consists of two sublayers: (i) ... [J. Appl. Phys. 101, 054512 (2007)] published Fri Mar 9, 2007.
Magnetic phase diagram and structural separation of La[sub 0.7](Ca[sub 1 - y]Sr[sub y])[sub 0.3]MnO[sub 3] thin films
Y. P. Lee, S. Y. Park, J. S. Park, V. G. Prokhorov, V. A. Komashko et al.
The structural, magnetic, and transport properties of La[sub 0.7](Ca[sub 1y]Sr[sub y])[sub 0.3]MnO[sub 3] films, deposited on a LaAlO[sub 3] (001) single crystalline substrate by rf-magnetron sputtering using soft (or powder) targets, have been investigated. It was found that at 0.3<=y<=0.5 both the ... [J. Appl. Phys. 101, 053708 (2007)] published Fri Mar 9, 2007.
Plasma window characterization
Ya. E. Krasik, S. Gleizer, V. Gurovich, I. Kronhaus, A. Hershcovitch et al.
Parameters of an arc Ar plasma discharge used as a plasma window with a discharge current of ~50 A and a voltage of ~58 V are presented. It is shown that this arc discharge allows one to decrease the pressure at the low pressure end of the plasma window almost 380 times using relatively low pumpin ... [J. Appl. Phys. 101, 053305 (2007)] published Fri Mar 9, 2007.
The influence of the H[sub 2]/Ar ratio on surface morphology and structural defects in homoepitaxial 4H-SiC films grown with methyltrichlorosilane
P. Lu and J. H. Edgar
Characterization of surface morphology and crystal defects is reported for homoepitaxial 4H-SiC films grown at high rates (3540 [mu]m/h) using methyltrichlorosilane (CH[sub 3]SiCl[sub 3]), as single precursor. The ratio of hydrogen to argon (H[sub 2]/Ar) in the carrier gas was varied to determine t ... [J. Appl. Phys. 101, 054513 (2007)] published Fri Mar 9, 2007.
Effect of ultrasound on the heterogeneous nucleation of BaSO[sub 4] during reactive crystallization
Z. Guo, A. G. Jones, H. Hao, B. Patel, and N. Li
The effect of ultrasound on reactive crystallization is studied by measuring the induction time when nucleation is predominantly heterogeneous. Barium sulphate is used as the working substance precipitated by mixing aqueous BaCl[sub 2] and Na[sub 2]SO[sub 4] solutions with relatively low concentrati ... [J. Appl. Phys. 101, 054907 (2007)] published Fri Mar 9, 2007.
Coalescence aspects of III-nitride epitaxy
V. Lebedev, K. Tonisch, F. Niebelschutz, V. Cimalla, D. Cengher et al.
In this work, coalescence aspects of wurtzite-III-nitride epitaxy are addressed. The coalescence phenomena have been studied in thin epilayers by means of electron and atomic force microscopies, and electron and x-ray diffractions. This study generalizes the growth parameters responsible for the rap ... [J. Appl. Phys. 101, 054906 (2007)] published Fri Mar 9, 2007.
Monocrystalline hexagonal-close-packed and polycrystalline face-centered-cubic Co nanowire arrays fabricated by pulse dc electrodeposition
Jun Zhang, Grenville A. Jones, Tiehan H. Shen, Steve E. Donnelly, and Guanghai Li
Cobalt nanowire arrays have been grown onto anodic aluminum oxide templates by using a pulse dc electrodeposition technique. We demonstrate that the crystal structure, grain size, and related magnetic properties can be controlled by applying different pulse frequencies. For a pulse frequency of 25 ... [J. Appl. Phys. 101, 054310 (2007)] published Fri Mar 9, 2007.
Dissociation of Si[sup +] ion implanted and as-grown thin SiO[sub 2] layers during annealing in ultra-pure neutral ambient by emanation of SiO
V. Beyer, J. von Borany, and K.-H. Heinig
We have observed a very inhomogeneous dissociation of stoichiometric and non-stoichiometric thin SiO[sub 2] layers (thermally grown on Si substrates) during high temperature annealing at a low partial pressure of oxygen. During this process some silicon of the (100)Si substrate and, in case of Si io ... [J. Appl. Phys. 101, 053516 (2007)] published Fri Mar 9, 2007.
Quantitative structural characterization of GaN quantum dot ripening using reflection high-energy electron diffraction
J. Coraux, V. Favre-Nicolin, H. Renevier, M. G. Proietti, B. Amstatt et al.
Reflection high-energy electron diffraction (RHEED) was used to monitor the strain of GaN/AlN quantum dots (QDs) grown by molecular beam epitaxy. Quantitative and absolute values of the in- and out-of-plane strains of the QDs were determined and compared to reference values, obtained by x-ray diffra ... [J. Appl. Phys. 101, 056106 (2007)] published Fri Mar 9, 2007.
Interpreting magnetization from Faraday rotation in birefringent magnetic media
S. R. Woodford, A. Bringer, and S. Blugel
The Faraday effect is an extremely useful probe of magnetization dynamics on an ultrafast scale. However, the measured Faraday rotation is difficult to interpret in birefringent media. We investigate the link between magnetization and Faraday rotation by solving Maxwell's equations in a magnetically ... [J. Appl. Phys. 101, 053912 (2007)] published Fri Mar 9, 2007.
Impacts of growth parameters on deep levels in n-type 4H-SiC
Katsunori Danno, Tsutomu Hori, and Tsunenobu Kimoto
Deep levels in n-type 4H-SiC epilayers have been investigated by deep level transient spectroscopy. The Z[sub 1/2] and EH[sub 6/7] centers are dominant in epilayers grown with low C/Si ratios during chemical vapor deposition. By increasing the C/Si ratio, the Z[sub 1/2] and EH[sub 6/7] concentration ... [J. Appl. Phys. 101, 053709 (2007)] published Fri Mar 9, 2007.
Electrical analysis of positive corona discharge in air and N[sub 2], O[sub 2], and CO[sub 2] mixtures
D. Dubois, N. Merbahi, O. Eichwald, M. Yousfi, and M. Benhenni
This paper presents an experimental analysis of the electrical behavior of positive point-plane corona discharges. The corona current, streamer velocity, mean discharge frequency, and current-voltage characteristic are studied, firstly in synthetic air as a function of experimental parameters such a ... [J. Appl. Phys. 101, 053304 (2007)] published Fri Mar 9, 2007.
Europhysics Letters (EPL)
Interface tension of the square lattice Ising model with next-nearest-neighbour interactions
Authors: A. Nußbaumer, E. Bittner and W. Janke
EPL 78, (2007) received 20 December 2006; accepted in final form 19 February 2007; published April 2007
Pacs: 68.35.Rh - Phase transitions and critical phenomena, 02.70.Uu - Applications of Monte Carlo methods, 75.10.Hk - Classical spin models
Pore opening effects and transport diffusion in the Knudsen regime in comparison to self- (or tracer-) diffusion
Authors: S. Zschiegner, S. Russ, A. Bunde and J. Kärger
EPL 78, (2007) received 13 December 2006; accepted in final form 23 February 2007; published April 2007
Pacs: 05.40.Fb - Random walks and Levy flights, 66.30.Pa - Diffusion in nanoscale solids, 82.56.Lz - Diffusion
Synchronization properties of network motifs
Authors: I. Lodato, S. Boccaletti and V. Latora
EPL 78, (2007) received 7 November 2006; accepted in final form 26 February 2007; published April 2007
Pacs: 89.75.-k - Complex systems, 05.45.Xt - Synchronization; coupled oscillators, 87.18.Sn - Neural networks
Einstein vs. Maxwell: Is gravitation a curvature of space, a field in flat space, or both?
Author: T. M. Nieuwenhuizen
EPL 78, (2007) received 12 October 2006; accepted in final form 12 February 2007; published April 2007
Pacs: 04.20.Cv - Fundamental problems and general formalism, 04.20.Fy - Canonical formalism, Lagrangians, and variational principles, 98.80.Bp - Origin and formation of the Universe
Diffusion and dispersion of passive tracers: Navier-Stokes vs. MHD turbulence
Authors: W.-C. Müller and A. Busse
EPL 78, (2007) received 6 December 2006; accepted in final form 22 February 2007; published April 2007
Pacs: 47.10.-g - General theory in fluid dynamics, 47.27.-i - Turbulent flows, 52.30.Cv - Magnetohydrodynamics (including electron magnetohydrodynamics)
High-field magnetization measurements in Sr_{2}CrReO_{6} double perovskite: Evidence for orbital contribution to the magnetization
Authors: J. M. Michalik, J. M. De Teresa, C. Ritter, J. Blasco, D. Serrate, M. R. Ibarra, C. Kapusta, J. Freudenberger and N. Kozlova
EPL 78, (2007) received 22 November 2006; accepted in final form 21 February 2007; published April 2007
Pacs: 75.30.Cr - Saturation moments and magnetic susceptibilities, 61.12.Ld - Neutron diffraction, 61.10.Nz - X-ray diffraction
Spin-density induced by electromagnetic wave in two-dimensional electron gas
Authors: A. Shnirman and I. Martin
EPL 78, (2007) received 1 November 2006; accepted in final form 22 February 2007; published April 2007
Pacs: 72.25.Rb - Spin relaxation and scattering, 85.75.-d - Magnetoelectronics; spintronics: devices exploiting spin polarized transport or integrated magnetic fields
Interface reorientation during coherent phase transformations
Authors: V. I. Levitas, I. B. Ozsoy and D. L. Preston
EPL 78, (2007) received 7 December 2006; accepted in final form 21 February 2007; published April 2007
Non-monotonicity and divergent time scale in Axelrod model dynamics
Authors: F. Vazquez and S. Redner
EPL 78, (2007) received 1 September 2006; accepted in final form 17 February 2007; published April 2007
Pacs: 89.65.-s - Social and economic systems, 02.50.Ey - Stochastic processes, 05.40.-a - Fluctuation phenomena, random processes, noise, and Brownian motion
Deviation from Gaussianity in the cosmic microwave background temperature fluctuations
Authors: Armando Bernui, Constantino Tsallis and Thyrso Villela
EPL 78, (2007) received 6 October 2006; accepted in final form 19 February 2007; published April 2007
Pacs: 98.80.Es - Observational cosmology (including Hubble constant, distance scale, cosmological constant, early Universe, etc.), 98.70.Vc - Background radiations, 05.90.+m - Other topics in statistical physics, thermodynamics, and nonlinear dynamical systems
Hypothesis of strong chaos and anomalous diffusion in coupled symplectic maps
Authors: E. G. Altmann and H. Kantz
EPL 78, (2007) received 7 November 2006; accepted in final form 19 February 2007; published April 2007
Pacs: 05.45.Jn - High-dimensional chaos, 05.40.Fb - Random walks and Levy flights, 05.60.Cd - Classical transport
Coherently controlled entanglement generation in a binary Bose-Einstein condensate
Authors: N. Teichmann and C. Weiss
EPL 78, (2007) received 27 September 2006; accepted in final form 15 February 2007; published April 2007
Pacs: 03.75.Gg - Entanglement and decoherence in Bose-Einstein condensates, 03.75.Lm - Tunneling, Josephson effect, Bose-Einstein condensates in periodic potentials, solitons, vortices, and topological excitations, 03.75.Mn - Multicomponent condensates; spinor condensates
Ab initio study of surface stress response to charging
Authors: Y. Umeno, C. Elsässer, B. Meyer, P. Gumbsch, M. Nothacker, J. Weissmüller and F. Evers
EPL 78, (2007) received 28 October 2006; accepted in final form 13 February 2007; published April 2007
Pacs: 31.15.Ar - Ab initio calculations, 73.30.+y - Surface double layers, Schottky barriers, and work functions, 68.35.Gy - Mechanical properties; surface strains
The Eulerian description of dilute collisionless suspension
Authors: G. Boffetta, A. Celani, F. De Lillo and S. Musacchio
EPL 78, (2007) received 11 October 2006; accepted in final form 15 February 2007; published April 2007
Non-linear elastic effects in plasticity: \mth{\{100\}} dislocation gliding in aluminum-based alloy
Authors: J. Colin, P. Beauchamp, S. Brochard, J. Grilhé and A. Coujou
EPL 78, (2007) received 4 October 2006; accepted in final form 16 February 2007; published April 2007
Pacs: 61.72.Lk - Linear defects: dislocations, disclinations, 62.20.Fe - Deformation and plasticity (including yield, ductility, and superplasticity), 61.72.Bb - Theories and models of crystal defects
Analysis of characteristic matrix for a uniaxially birefringent thin film
Authors: H. J. Qi, J. D. Shao and Z. X. Fan
EPL 78, (2007) received 30 December 2006; accepted in final form 15 February 2007; published April 2007
Pacs: 78.20.Fm - Birefringence, 78.20.Ci - Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity), 77.55.+f - Dielectric thin films
Role of symmetry in the interplay of \mth{T=0} quantum-phase transitions with unconventional \mth{T>0} transport properties in integrable quantum lattice systems
Authors: J. M. P. Carmelo, S.-J. Gu and N. M. R. Peres
EPL 78, (2007) received 2 October 2006; accepted in final form 13 February 2007; published April 2007
Pacs: 72.10.-d - Theory of electronic transport; scattering mechanisms, 71.27.+a - Strongly correlated electron systems; heavy fermions, 05.60.Gg - Quantum transport
Particle-based mesoscale hydrodynamic techniques
Authors: H. Noguchi, N. Kikuchi and G. Gompper
EPL 78, (2007) received 31 October 2006; accepted in final form 12 February 2007; published April 2007
Pacs: 02.70.-c - Computational techniques; simulations, 47.11.-j - Computational methods in fluid dynamics, 66.20.+d - Viscosity of liquids; diffusive momentum transport
Shot noise of interference between independent atomic systems
Author: A. Polkovnikov
EPL 78, (2007) received 4 December 2006; accepted in final form 13 February 2007; published April 2007
Pacs: 03.75.Dg - Atom and neutron interferometry, 03.75.Lm - Tunneling, Josephson effect, Bose-Einstein condensates in periodic potentials, solitons, vortices, and topological excitations
Equilibrium spin transport in the ferromagnet/ferromagnet tunnelling junction
Authors: Y. G. Shen and Z. H. Yang
EPL 78, (2007) received 23 November 2006; accepted in final form 14 February 2007; published April 2007
Pacs: 73.23.-b - Electronic transport in mesoscopic systems, 72.25.Dc - Spin polarized transport in semiconductors, 71.70.Ej - Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect
Hydrodynamic flow caused by active transport along cytoskeletal elements
Authors: D. Houtman, I. Pagonabarraga, C. P. Lowe, A. Esseling-Ozdoba, A. M. C. Emons and E. Eiser
EPL 78, (2007) received 9 July 2006; accepted in final form 12 February 2007; published April 2007
Pacs: 87.16.Nn - Motor proteins (myosin, kinesin dynein), 67.40.Hf - Hydrodynamics in specific geometries, flow in narrow channels, 05.40.-a - Fluctuation phenomena, random processes, noise, and Brownian motion
Intermittent exploration on a scale-free network
Author: A. Ramezanpour
EPL 77, (2007) received 27 August 2006; accepted in final form 2 February 2007; published March 2007
Pacs: 05.40.Fb - Random walks and Levy flights, 89.75.Hc - Networks and genealogical trees, 87.23.Ge - Dynamics of social systems
Fragmenting granular gases
Authors: R. Cruz Hidalgo and I. Pagonabarraga
EPL 77, (2007) received 30 June 2006; accepted in final form 26 January 2007; published March 2007
Pacs: 46.50.+a - Fracture mechanics, fatigue and cracks, 45.70.-n - Granular systems, 05.20.Dd - Kinetic theory
Liapunov functional for a delayed integro-differential equation model of a neural field
Authors: M. Enculescu and M. Bestehorn
EPL 77, (2007) received 18 September 2006; accepted in final form 2 February 2007; published March 2007
Pacs: 87.10.+e - General theory and mathematical aspects, 87.18.Sn - Neural networks, 05.45.-a - Nonlinear dynamics and chaos
Evidence for moving breathers in a layered crystal insulator at 300 K
Authors: F. M. Russell and J. C. Eilbeck
EPL 78, (2007) received 3 December 2006; accepted in final form 12 February 2007; published April 2007
Pacs: 05.45.Yv - Solitons, 43.25.+y - Nonlinear acoustics, 61.80.Lj - Atom and molecule irradiation effects
Dynamic crossover in the global persistence at criticality
Authors: R. Paul, A. Gambassi and G. Schehr
EPL 78, (2007) received 22 January 2007; accepted in final form 12 February 2007; published April 2007
Pacs: 05.70.Jk - Critical point phenomena, 05.50.+q - Lattice theory and statistics (Ising, Potts, etc.)
Observation of particle hole asymmetry and phonon excitations in non-Fermi-liquid systems: A high-resolution photoemission study of ruthenates
Authors: K. Maiti, R. S. Singh and V. R. R. Medicherla
EPL 78, (2007) received 13 November 2006; accepted in final form 13 February 2007; published April 2007
Pacs: 71.10.Hf - Non-Fermi-liquid ground states, electron phase diagrams and phase transitions in model systems, 63.20.Kr - Phonon-electron and phonon-phonon interactions, 71.45.Gm - Exchange, correlation, dielectric and magnetic response functions, plasmons
On the top eigenvalue of heavy-tailed random matrices
Authors: G. Biroli, J.-P. Bouchaud and M. Potters
EPL 78, (2007) received 16 November 2006; accepted in final form 10 February 2007; published April 2007
Pacs: 02.10.Yn - Matrix theory, 02.50.-r - Probability theory, stochastic processes, and statistics, 89.65.Gh - Economics; econophysics, financial markets, business and management
A ring accelerator for matter-wave solitons
Authors: A. V. Carpentier and H. Michinel
EPL 78, (2007) received 2 January 2007; accepted in final form 8 February 2007; published April 2007
Pacs: 03.75.Kk - Dynamic properties of condensates; collective and hydrodynamic excitations, superfluid flow, 03.75.Lm - Tunneling, Josephson effect, Bose-Einstein condensates in periodic potentials, solitons, vortices, and topological excitations
Collective skipping: Aperiodic phase locking in ensembles of bursting oscillators
Authors: G. Tanaka and K. Aihara
EPL 78, (2007) received 29 July 2006; accepted in final form 8 February 2007; published April 2007
Pacs: 05.45.-a - Nonlinear dynamics and chaos, 05.45.Xt - Synchronization; coupled oscillators, 87.18.Hf - Spatiotemporal pattern formation in cellular populations
Determining radial breathing mode frequencies of single-walled carbon nanotubes with an atomic force microscope
Authors: J. Fraxedas, G. Rius, F. Pérez-Murano and A. Verdaguer
EPL 78, (2007) received 11 January 2007; accepted in final form 12 February 2007; published April 2007
Pacs: 63.22.+m - Phonons or vibrational states in low-dimensional structures and nanoscale materials, 61.46.Fg - Nanotubes, 68.37.Ps - Atomic force microscopy (AFM)
Reduction of the RPA eigenvalue problem and a generalized Cholesky decomposition for real-symmetric matrices
Author: P. Papakonstantinou
EPL 78, (2007) received 28 November 2006; accepted in final form 7 February 2007; published April 2007
Pacs: 21.60.Jz - Hartree-Fock and random-phase approximations, 02.60.Dc - Numerical linear algebra, 02.10.Yn - Matrix theory
Magnetism depending on carrier in (Zn,Co)O
Authors: H.-J. Lee, H.-H. Nam, Y.-C. Cho, S.-K. Kim, C. H. Park, C. R. Cho and S.-Y. Jeong
EPL 78, (2007) received 20 October 2006; accepted in final form 6 February 2007; published April 2007
Pacs: 75.50.Pp - Magnetic semiconductors, 61.72.Vv - Doping and impurity implantation in III-V and II-VI semiconductors, 71.20.-b - Electron density of states and band structure of crystalline solids
Reply to the Comment by B. Aktaş
Authors: Yun-Song Zhou, Ben-Yuan Gu and Fu-He Wang
EPL 77, (2007) received 7 December 2006; accepted in final form 5 February 2007; published March 2007
Pacs: 41.20.Jb - Electromagnetic wave propagation; radiowave propagation, 73.20.Mf - Collective excitations (including excitons, polarons, plasmons, and other charge-density excitations), 78.20.Ci - Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
Design, fabrication and characteristic of two-layer microwave absorbers composed of magnetic micropowder-rubber composites in X-band frequency range
Authors: Yanfei He, Rongzhou Gong, Xiangcheng Li, Xian Wang and Qifa Hu
EPL 77, (2007) received 8 December 2006; accepted in final form 30 January 2007; published March 2007
Pacs: 81.05.-t - Specific materials: fabrication, treatment, testing, and analysis, 75.50.-y - Studies of specific magnetic materials, 07.05.Tp - Computer modeling and simulation
Comment on “Ferromagnetic wire lattice with a tunable negative index of refraction for microwaves using an external magnetic field” by Yun-Song Zhou et al.
Author: B. Aktaş
EPL 77, (2007) received 16 November 2006; accepted in final form 5 February 2007; published March 2007
Pacs: 41.20.Jb - Electromagnetic wave propagation; radiowave propagation, 73.20.Mf - Collective excitations (including excitons, polarons, plasmons, and other charge-density excitations), 78.20.Ci - Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmisson coefficients, emissivity)
Theory of the length distribution of tread-milling actin filaments inside bundles
Author: N. S. Gov
EPL 77, (2007) received 11 July 2006; accepted in final form 26 January 2007; published March 2007
Pacs: 87.16.Ka - Filaments, microtubules, their networks, and supramolecular assemblies, 87.15.Nn - Properties of solutions; aggregation and crystallization of macromolecules
Noise and poise: Enhancement of postural complexity in the elderly with a stochastic-resonance\hbox{--} based therapy
Authors: M. Costa, A. A. Priplata, L. A. Lipsitz, Z. Wu, N. E. Huang, A. L. Goldberger and C.-K. Peng
EPL 77, (2007) received 3 November 2006; accepted in final form 2 February 2007; published March 2007
Pacs: 89.75.-k - Complex systems, 87.19.La - Neuroscience, 05.45.Tp - Time series analysis
Effective surface-tension in the noise-reduced voter model
Authors: Luca Dall'Asta and Claudio Castellano
EPL 77, (2007) received 7 December 2006; accepted in final form 2 February 2007; published March 2007
Pacs: 05.40.-a - Fluctuation phenomena, random processes, noise, and Brownian motion, 02.50.-r - Probability theory, stochastic processes, and statistics, 89.65.-s - Social and economic systems
Magic angle detection of nonlinear Newton-Wigner times at interfaces
Authors: G. Loas, C. Bonnet, K. Dunseath, D. Chauvat, O. Emile and A. Le Floch
EPL 77, (2007) received 21 July 2006; accepted in final form 29 January 2007; published March 2007
Pacs: 42.25.Gy - Edge and boundary effects; reflection and refraction, 42.25.Ja - Polarization, 42.65.-k - Nonlinear optics
Refocussed relativistic recollisions
Authors: M. Verschl and C. H. Keitel
EPL 77, (2007) received 8 November 2006; accepted in final form 2 February 2007; published March 2007
Pacs: 41.75.Jv - Laser-driven acceleration, 34.80.Kw - Electron-ion scattering; excitation and ionization, 41.75.Ht - Relativistic electron and positron beams
Absence of logarithmic attraction between colloids trapped at the interface of droplets - Comment on “Capillary attraction of charged particles at a curved liquid interface” by Alois Würger
Authors: A. Domínguez, M. Oettel and S. Dietrich
EPL 77, (2007) received 23 October 2006; accepted in final form 26 January 2007; published March 2007
Pacs: 82.70.Dd - Colloids, 68.03.Cd - Surface tension and related phenomena
On the interface and boundary conditions in the parabolic equation method
Author: M. Yu. Trofimov
EPL 77, (2007) received 10 August 2006; accepted in final form 4 February 2007; published March 2007
Pacs: 43.20.Bi - Mathematical theory of wave propagation, 43.30.+m - Underwater sound, 43.20.+g - General linear acoustics
Alpha-decay lifetimes semiempirical relationship including shell effects
Authors: D. N. Poenaru, R. A. Gherghescu and N. Carjan
EPL 77, (2007) received 9 October 2006; accepted in final form 5 February 2007; published March 2007
Pacs: 23.60.+e - \alpha decay, 21.10.Tg - Lifetimes, 27.90.+b - Properties of specific nuclei listed by mass ranges: 220 \leqslant A
How to measure functional RG fixed-point functions for dynamics and at depinning
Authors: P. Le Doussal and K. J. Wiese
EPL 77, (2007) received 19 October 2006; accepted in final form 25 January 2007; published March 2007
Theory of one-dimensional double-barrier quantum pump in two-frequency signal regime
Authors: M. M. Mahmoodian and M. V. Entin
EPL 77, (2007) received 8 December 2006; accepted in final form 2 February 2007; published March 2007
Pacs: 73.23.-b - Electronic transport in mesoscopic systems, 73.50.Pz - Photoconduction and photovoltaic effects, 85.35.Be - Quantum well devices (quantum dots, quantum wires, etc.)
Discontinuity of the chemical potential in reduced-density-matrix-functional theory
Authors: N. Helbig, N. N. Lathiotakis, M. Albrecht and E. K. U. Gross
EPL 77, (2007) received 10 October 2006; accepted in final form 2 February 2007; published March 2007
Pacs: 71.10.-w - Theories and models of many-electron systems, 31.10.+z - Theory of electronic structure, electronic transitions, and chemical binding, 31.15.Ew - Density-functional theory
Rate- and state-dependent friction law and statistical properties of earthquakes
Authors: A. Ohmura and H. Kawamura
EPL 77, (2007) received 6 November 2006; accepted in final form 2 February 2007; published March 2007
Leakage conduction mechanism of amorphous \chem{Lu_{2}O_{3}} high-\mth{k} dielectric films fabricated by pulsed laser ablation
Authors: C. L. Yuan, P. Darmawan, M. Y. Chan and P. S. Lee
EPL 77, (2007) received 6 December 2006; accepted in final form 30 January 2007; published March 2007
Pacs: 77.55.+f - Dielectric thin films, 72.80.Sk - Insulators, 73.40.Qv - Metal-insulator-semiconductor structures (including semiconductor-to- insulator)
Magnetic-field-induced chain-like assembly structures of \chem{Fe_{3}O_{4}} nanoparticles
Authors: W.-X. Fang, Z.-H. He, X.-Q. Xu, Z.-Q. Mao and H. Shen
EPL 77, (2007) received 31 August 2006; accepted in final form 26 January 2007; published March 2007
Pacs: 81.16.Dn - Self-assembly, 75.50.Mm - Magnetic liquids, 82.35.-x - Polymers: properties; reactions; polymerization
Single file diffusion enhancement in a fluctuating modulated quasi-1D channel
Authors: G. Coupier, M. Saint Jean and C. Guthmann
EPL 77, (2007) received 23 October 2006; accepted in final form 25 January 2007; published March 2007
Colloid-polymer mixtures between asymmetric walls: Evidence for an interface localization transition
Authors: A. De Virgiliis, R. L. C. Vink, J. Horbach and K. Binder
EPL 77, (2007) received 13 September 2006; accepted in final form 26 January 2007; published March 2007
Pacs: 05.70.Jk - Critical point phenomena, 64.60.Fr - Equilibrium properties near critical points, critical exponents, 68.08.Bc - Wetting
How to measure the wave function absolute squared of a moving particle by using mirrors
Authors: V. Hannstein and G. C. Hegerfeldt
EPL 77, (2007) received 20 October 2006; accepted in final form 31 January 2007; published March 2007
Pacs: 03.65.Wj - State reconstruction, quantum tomography, 03.75.Be - Atom and neutron optics, 32.80.Lg - Mechanical effects of light on atoms, molecules, and ions
Vortex density spectrum of quantum turbulence
Authors: P.-E. Roche, P. Diribarne, T. Didelot, O. Français, L. Rousseau and H. Willaime
EPL 77, (2007) received 25 October 2006; accepted in final form 29 January 2007; published March 2007
Pacs: 67.40.Vs - Vortices and turbulence, 47.37.+q - Hydrodynamic aspects of superfluidity; quantum fluids, 67.57.De - Quantum fluids and solids; liquid and solid helium: Superflow and hydro- dynamics
In situ observation of stereoscopic shapes of cavities in soft adhesives
Authors: T. Yamaguchi, K. Koike and M. Doi
EPL 77, (2007) received 11 October 2006; accepted in final form 26 January 2007; published March 2007
Pacs: 47.55.dp - Cavitation and boiling, 68.35.Np - Adhesion
Stretching helical nano-springs at finite temperature
Authors: H. Wada and R. R. Netz
EPL 77, (2007) received 5 December 2006; accepted in final form 25 January 2007; published March 2007
Pacs: 87.15.-v - Biomolecules: structure and physical properties, 62.25.+g - Mechanical properties of nanoscale materials, 82.37.Gk - STM and AFM manipulations of a single molecule
Reply to the Comment by A. Domínguez et al.
Author: Alois Würger
EPL 77, (2007) received 7 November 2006; accepted in final form 26 January 2007; published March 2007
A theory for critically divergent fluctuations of dynamical events at non-ergodic transitions
Authors: M. Iwata and S. Sasa
EPL 77, (2007) received 14 September 2006; accepted in final form 22 January 2007; published March 2007
Pacs: 05.40.-a - Fluctuation phenomena, random processes, noise, and Brownian motion, 02.50.-r - Probability theory, stochastic processes, and statistics, 64.70.Pf - Glass transitions
Flux qubit as a sensor of magnetic flux
Authors: E. Il'ichev and Ya. S. Greenberg
EPL 77, (2007) received 17 November 2006; accepted in final form 17 January 2007; published March 2007
Pacs: 85.25.Cp - Josephson devices, 85.25.Dq - Superconducting quantum interference devices (SQUIDs), 84.37.+q - Measurements in electric variables (including voltage, current, resistance, capacitance, inductance, impedance, and admittance, etc.)
Achieving synchronization of networks by an auxiliary hub
Authors: D. Huang and G. Pipa
EPL 77, (2007) received 16 October 2006; accepted in final form 23 January 2007; published March 2007
Pacs: 05.45.Xt - Synchronization; coupled oscillators, 89.75.-k - Complex systems, 87.18.Sn - Neural networks
A non-Markovian optical signature for detecting entanglement in coupled excitonic qubits
Authors: F. J. Rodríguez, L. Quiroga and N. F. Johnson
EPL 77, (2007) received 4 August 2006; accepted in final form 23 January 2007; published March 2007
Pacs: 03.65.Yz - Decoherence; open systems; quantum statistical methods, 03.65.Ud - Entanglement and quantum nonlocality, 78.67.Hc - Quantum dots
Observation of phasons in the magnetic shape memory alloy \chem{Ni_{2}MnGa}
Authors: S. M. Shapiro, P. Vorderwisch, K. Habicht, K. Hradil and H. Schneider
EPL 77, (2007) received 9 November 2006; accepted in final form 17 January 2007; published March 2007
Pacs: 61.12.-q - Neutron diffraction and scattering, 71.45.Lr - Charge-density-wave systems, 81.30.Kf - Martensitic transformations
Solving Hartree-Fock systems with global optimization methods
Authors: C. Lavor, L. Liberti, N. Maculan and M. A. C. Nascimento
EPL 77, (2007) received 21 September 2006; accepted in final form 11 January 2007; published March 2007
Pacs: 02.60.Pn - Numerical optimization, 31.15.Ar - Ab initio calculations, 71.15.Dx - Computational methodology (Brillouin zone sampling, iterative diagonalization, pseudopotential construction)
Magnetic field reversals in an experimental turbulent dynamo
Authors: M. Berhanu, R. Monchaux, S. Fauve, N. Mordant, F. Pétrélis, A. Chiffaudel, F. Daviaud, B. Dubrulle, L. Marié, F. Ravelet, M. Bourgoin, Ph. Odier, J.-F. Pinton and R. Volk
EPL 77, (2007) received 22 December 2006; accepted in final form 12 February 2007; published March 2007
Pacs: 91.25.Cw - Origins and models of the magnetic field; dynamo theories, 47.65.-d - Magnetohydrodynamics and electrohydrodynamics
Erratum: Phase transitions in lead-free piezoelectric ceramics: Study of local atomic structure
Authors: M. P. Lemeshko, E. S. Nazarenko, A. A. Gonchar, L. A. Reznichenko, O. Mathon, Y. Joly and R. V. Vedrinskii
EPL 77, (2007) received 5 February 2007; accepted in final form 5 February 2007; published March 2007
Optimal control of dissipation for the example of the spin-boson model
Authors: H. Jirari and W. Pötz
EPL 77, (2007) received 22 December 2006; accepted in final form 10 January 2007; published March 2007
Pacs: 02.30.Yy - Control theory, 03.65.Yz - Decoherence; open systems; quantum statistical methods
Exploring the van der Waals atom-surface attraction in the nanometric range
Authors: M. Fichet, G. Dutier, A. Yarovitsky, P. Todorov, I. Hamdi, I. Maurin, S. Saltiel, D. Sarkisyan, M.-P. Gorza, D. Bloch and M. Ducloy
EPL 77, (2007) received 6 November 2006; accepted in final form 17 January 2007; published March 2007
Pacs: 42.50.Xa - Optical tests of quantum theory, 34.50.Dy - Interactions of atoms and molecules with surfaces; photon and electron emission; neutralization of ions, 32.70.Jz - Line shapes, widths, and shifts
Why polymer chains in a melt are not random walks
Authors: J. P. Wittmer, P. Beckrich, A. Johner, A. N. Semenov, S. P. Obukhov, H. Meyer and J. Baschnagel
EPL 77, (2007) received 24 October 2006; accepted in final form 11 January 2007; published March 2007
Pacs: 61.25.Hq - Macromolecular and polymer solutions; polymer melts; swelling, 64.60.Ak - Renormalization-group, fractal, and percolation studies of phase transitions, 05.10.Ln - Monte Carlo methods
Monitoring approach to open quantum dynamics using scattering theory
Author: K. Hornberger
EPL 77, (2007) received 11 December 2006; accepted in final form 16 January 2007; published March 2007
Pacs: 03.65.Yz - Decoherence; open systems; quantum statistical methods, 03.65.Nk - Scattering theory, 34.10.+x - General theories and models of atomic and molecular collisions and interactions (including statistical theories, transition state, stochastic and trajectory models, etc.)
Exchange bias in granular CoO layers due to random magnetic anisotropy
Author: M. Gruyters
EPL 77, (2007) received 9 October 2006; accepted in final form 19 January 2007; published March 2007
Pacs: 75.70.-i - Magnetic properties of thin films, surfaces, and interfaces, 75.50.Ee - Antiferromagnetics, 75.50.Lk - Spin glasses and other random magnets
Filamentous networks in phase-separating two-dimensional gels
Authors: O. Peleg, M. Kröger, I. Hecht and Y. Rabin
EPL 77, (2007) received 20 October 2006; accepted in final form 19 January 2007; published March 2007
Pacs: 82.70.Gg - Gels and sols, 64.70.Kb - Solid-solid transitions, 68.55.Ac - Nucleation and growth: microscopic aspect
Growing network with j-redirection
Authors: R. Lambiotte and M. Ausloos
EPL 77, (2007) received 4 December 2006; accepted in final form 8 January 2007; published March 2007
Pacs: 89.75.Fb - Structures and organization in complex systems, 87.23.Ge - Dynamics of social systems, 89.75.Hc - Networks and genealogical trees
Second-type disorder in colloidal crystals
Authors: R. P. A. Dullens and A. V. Petukhov
EPL 77, (2007) received 6 October 2006; accepted in final form 10 January 2007; published March 2007
Pacs: 82.70.Dd - Colloids, 61.72.-y - Defects and impurities in crystals; microstructure, 61.10.-i - X-ray diffraction and scattering
Self-organization of price fluctuation distribution in evolving markets
Authors: R. K. Pan and S. Sinha
EPL 77, (2007) received 21 June 2006; accepted in final form 16 January 2007; published March 2007
Pacs: 89.65.Gh - Economics; econophysics, financial markets, business and management, 89.65.-s - Social and economic systems, 05.65.+b - Self-organized systems
Effect of memory kernels on the speed of reaction-diffusion fronts
Authors: V. Méndez, S. Fedotov and W. Horsthemke
EPL 77, (2007) received 2 August 2006; accepted in final form 18 January 2007; published March 2007
Pacs: 87.10.+e - Biological and medical physics: general theory and mathematical aspects, 05.40.-a - Fluctuation phenomena, random processes, noise and Brownian motion, 05.60.Cd - Classical transport
Effects of the littlest Higgs model with T-parity on Higgs boson production at high-energy \mth{e^{+}e^{-}} colliders
Authors: Chong-Xing Yue and Nan Zhang
EPL 77, (2007) received 16 November 2006; accepted in final form 9 January 2007; published March 2007
Pacs: 12.60.Cn - Extensions of electroweak gauge sector, 13.66.Fg - Gauge and Higgs boson production in e^+ e^- interactions, 14.80.Cp - Non-standard-model Higgs bosons
Relevant coherent states method for the quantum adiabatic dynamics of lattice-coupled charge carriers
Author: O. S. Barišić
EPL 77, (2007) received 12 September 2006; accepted in final form 9 January 2007; published March 2007
Pacs: 71.38.-k - Polarons and electron-phonon interactions, 63.20.Kr - Phonon-electron and phonon-phonon interactions
Intraband vs. interband scattering rate effects in neutron irradiated MgB_{2}
Authors: M. Putti, P. Brotto, M. Monni, E. Galleani d'Agliano, A. Sanna and S. Massidda
EPL 77, (2007) received 27 November 2006; accepted in final form 10 January 2007; published March 2007
Pacs: 74.70.Ad - Metals; alloys and binary compounds (including A15, MgB{_2}, etc.), 61.80.Hg - Neutron radiation effects, 74.62.Dh - Effects of crystal defects, doping and substitution
Physical Review Letters (PRL)
Publisher’s Note: Oxygen Vacancy Clustering and Electron Localization in Oxygen-Deficient SrTiO_{3}: LDA+U Study [Phys. Rev. Lett. 98, 115503 (2007)]
Author(s): D. D. Cuong et al.
[Phys. Rev. Lett. 98, 129903] Published Thu Mar 22, 2007
Chain Conformations and Bound-Layer Correlations in Polymer Nanocomposites
Author(s): S. Sen et al.
Small angle neutron scattering studies on polystyrene loaded with spherical silica nanoparticles under contrast-matched conditions unequivocally show that chain conformations follow unperturbed Gaussian statistics independent of chain molecular weight and filler composition. Liquid state theory cal...
[Phys. Rev. Lett. 98, 128302] Published Thu Mar 22, 2007
Dynamical Origin of Independent Spiking and Bursting Activity in Neural Microcircuits
Author(s): T. Nowotny and M. I. Rabinovich
The relationship between spiking and bursting dynamics is a key question in neuroscience, particularly in understanding the origins of different neural coding strategies and the mechanisms of motor command generation and neural circuit coordination. Experiments indicate that spiking and bursting dy...
[Phys. Rev. Lett. 98, 128106] Published Thu Mar 22, 2007
Experimental Signature of Phonon-Mediated Spin Relaxation in a Two-Electron Quantum Dot
Author(s): T. Meunier et al.
We observe an experimental signature of the role of phonons in spin relaxation between triplet and singlet states in a two-electron quantum dot. Using both the external magnetic field and the electrostatic confinement potential, we change the singlet-triplet energy splitting from 1.3 meV to zero an...
[Phys. Rev. Lett. 98, 126601] Published Thu Mar 22, 2007
Superconductivity and Magnetic Order in CeRhIn_{5}: Spectra of Coexistence
Author(s): J. V. Alvarez and F. Yndurain
We discuss the fixed-point Hamiltonian and the spectrum of excitations of a quasi-bidimensional electronic system supporting simultaneously antiferromagnetic ordering and superconductivity. The coexistence of these two order parameters in a single phase is possible because the magnetic order is lin...
[Phys. Rev. Lett. 98, 126406] Published Thu Mar 22, 2007
Nanomechanical Energy Transfer and Resonance Effects in Single-Walled Carbon Nanotubes
Author(s): P. A. Greaney and J. C. Grossman
Molecular dynamics simulations are employed to elucidate the important factors in mechanical energy transfer between carbon nanotubes. Our calculations show that sharp resonance effects allow for near complete and highly efficient energy transfer. In addition, the weak coupling between two nanotube...
[Phys. Rev. Lett. 98, 125503] Published Thu Mar 22, 2007
Scaling and Universality in Rock Fracture
Author(s): J. Davidsen, S. Stanchits, and G. Dresen
We present a detailed statistical analysis of acoustic emission time series from laboratory rock fracture obtained from different experiments on different materials including acoustic emission controlled triaxial fracture and punch-through tests. In all considered cases, the waiting time distributi...
[Phys. Rev. Lett. 98, 125502] Published Thu Mar 22, 2007
Hydrodynamics beyond Navier-Stokes: Exact Solution to the Lattice Boltzmann Hierarchy
Author(s): S. Ansumali, I. V. Karlin, S. Arcidiacono, A. Abbas, and N. I. Prasianakis
The exact solution to the hierarchy of nonlinear lattice Boltzmann (LB) kinetic equations in the stationary planar Couette flow is found at nonvanishing Knudsen numbers. A new method of solving LB kinetic equations which combines the method of moments with boundary conditions for populations enable...
[Phys. Rev. Lett. 98, 124502] Published Thu Mar 22, 2007
Dynamics of Light-Field Control of Molecular Dissociation at the Few-Cycle Limit
Author(s): X. M. Tong and C. D. Lin
We studied the laser-molecule interaction dynamics that leads to the asymmetric D^{+} ion ejection in the dissociative ionization of D_{2} molecules observed recently in Kling et al. [Science 312, 246 (2006)]. By changing the carrier-envelope phase, we showed that the asymmetry is a consequence of ...
[Phys. Rev. Lett. 98, 123002] Published Thu Mar 22, 2007
NMR Experiment Factors Numbers with Gauss Sums
Author(s): M. Mehring, K. Müller, I. Sh. Averbukh, W. Merkel, and W. P. Schleich
We factor the number 157573 using an NMR implementation of Gauss sums. Although the current implementation is classical and scales exponentially, we believe that an extension to the quantum regime using entangled states is possible.![]()
[Phys. Rev. Lett. 98, 120502] Published Thu Mar 22, 2007
Erratum: Linear Stark Shift in Dressed Atoms as a Signal to Measure a Nuclear Anapole Moment with a Cold-Atom Fountain or Interferometer [Phys. Rev. Lett. 98, 043003 (2007)]
Author(s): M.-A. Bouchiat
[Phys. Rev. Lett. 98, 129902] Published Wed Mar 21, 2007
Exploring the Mechanism of Flexible Biomolecular Recognition with Single Molecule Dynamics
Author(s): Q. Lu, H. P. Lu, and J. Wang
Combining a single-molecule study of protein binding with a coarse grained molecular dynamics model including solvent (water molecules) effects, we find that biomolecular recognition is determined by flexibilities in addition to structures. Our single-molecule study shows that binding of CBD (a fra...
[Phys. Rev. Lett. 98, 128105] Published Wed Mar 21, 2007
Conformational Temperature Characterizing the Folding of a Protein
Author(s): N. Nakagawa
The time sequences of the molecular dynamics simulation for the folding process of a protein is analyzed with the inherent structure landscape which focuses on the configurational dynamics of the system. Time-dependent energy and entropy for inherent structures are introduced, and from these quanti...
[Phys. Rev. Lett. 98, 128104] Published Wed Mar 21, 2007
Swinging and Tumbling of Fluid Vesicles in Shear Flow
Author(s): H. Noguchi and G. Gompper
The dynamics of fluid vesicles in simple shear flow is studied using mesoscale simulations of dynamically triangulated surfaces, as well as a theoretical approach based on two variables: a shape parameter and the inclination angle, which has no adjustable parameters. We show that, between the well-...
[Phys. Rev. Lett. 98, 128103] Published Wed Mar 21, 2007
Competing Ferromagnetic and Charge-Ordered States in Models for Manganites: The Origin of the Colossal Magnetoresistance Effect
Author(s): C. Şen, G. Alvarez, and E. Dagotto
The one-orbital model for manganites with cooperative phonons and superexchange coupling J_{AF} is investigated via large-scale Monte Carlo simulations. The results for two orbitals are also briefly discussed. Focusing on the electron density n=0.75, a regime of competition between ferromagnetic me...
[Phys. Rev. Lett. 98, 127202] Published Wed Mar 21, 2007
Quantum Metallicity on the High-Field Side of the Superconductor-Insulator Transition
Author(s): T. I. Baturina, C. Strunk, M. R. Baklanov, and A. Satta
We investigate ultrathin superconducting TiN films, which are very close to the localization threshold. Perpendicular magnetic field drives the films from the superconducting to an insulating state, with very high resistance. Further increase of the magnetic field leads to an exponential decay of t...
[Phys. Rev. Lett. 98, 127003] Published Wed Mar 21, 2007
Room-Temperature Polariton Lasing in Semiconductor Microcavities
Author(s): S. Christopoulos et al.
We observe a room-temperature low-threshold transition to a coherent polariton state in bulk GaN microcavities in the strong-coupling regime. Nonresonant pulsed optical pumping produces rapid thermalization and yields a clear emission threshold of 1 mW, corresponding to an absorbed energy density o...
[Phys. Rev. Lett. 98, 126405] Published Wed Mar 21, 2007
Atomistic Underpinnings for Orientation Selection in Alloy Dendritic Growth
Author(s): C. A. Becker, D. Olmsted, M. Asta, J. J. Hoyt, and S. M. Foiles
In dendritic solidification, growth morphologies often display a pronounced sensitivity to small changes in composition. To gain insight into the origins of this phenomenon, we undertake an atomistic calculation of the magnitude and anisotropy of the crystal-melt interfacial free energy in a model ...
[Phys. Rev. Lett. 98, 125701] Published Wed Mar 21, 2007
Carrier-Density-Dependent Lattice Stability in InSb
Author(s): P. B. Hillyard et al.
The ultrafast decay of the x-ray diffraction intensity following laser excitation of an InSb crystal has been utilized to observe carrier dependent changes in the potential energy surface. For the first time, an abrupt carrier dependent onset for potential energy surface softening and the appearanc...
[Phys. Rev. Lett. 98, 125501] Published Wed Mar 21, 2007
Oscillatory Instability in Two-Dimensional Dynamic Fracture
Author(s): E. Bouchbinder and I. Procaccia
The stability of a rapid dynamic crack in a two-dimensional infinite strip is studied in the framework of linear elastic fracture mechanics supplemented with a modified principle of local symmetry. It is predicted that a single crack becomes unstable by a finite wavelength oscillatory mode at a vel...
[Phys. Rev. Lett. 98, 124302] Published Wed Mar 21, 2007
Oscillations in Rapid Fracture
Author(s): A. Livne, O. Ben-David, and J. Fineberg
Experiments of pure tensile fracture in thin brittle gels reveal a new dynamic oscillatory instability whose onset occurs at a critical velocity, V_{C}=0.87C_{S}, where C_{S} is the shear wave speed. Until V_{C}, crack dynamics are well described by linear elastic fracture mechanics (LEFM). These e...
[Phys. Rev. Lett. 98, 124301] Published Wed Mar 21, 2007
Observation of Two-Dimensional Surface Solitons
Author(s): X. Wang et al.
We report the first experimental observation of two-dimensional surface solitons at the boundaries (edges or corners) of a finite optically induced photonic lattice. Both in-phase and gap nonlinear surface self-trapped states were observed under single-site excitation conditions. Our experimental r...
[Phys. Rev. Lett. 98, 123903] Published Wed Mar 21, 2007
Anisotropic Explosions of Hydrogen Clusters under Intense Femtosecond Laser Irradiation
Author(s): D. R. Symes, M. Hohenberger, A. Henig, and T. Ditmire
We report on measurements of ion energy distributions from hydrogen clusters irradiated by intense laser pulses of duration 40 and 250 fs. Contrary to the predictions of a simple Coulomb explosion model, we observe a pronounced spatial anisotropy of the ion energies from these explosions with the h...
[Phys. Rev. Lett. 98, 123401] Published Wed Mar 21, 2007
Electron Collisions with Formic Acid Monomer and Dimer
Author(s): M. Allan
Processes induced by the attachment of slow electrons to formic acid and its hydrogen-bonded dimer were studied. The elastic cross section and the cross section for the excitation of low quanta of discrete vibrations were found to be of a similar magnitude for both targets. A dramatic difference wa...
[Phys. Rev. Lett. 98, 123201] Published Wed Mar 21, 2007
^{12}C+^{12}C Fusion Reactions near the Gamow Energy
Author(s): T. Spillane et al.
The fusion reactions ^{12}C(^{12}C,α)^{20}Ne and ^{12}C(^{12}C,p)^{23}Na have been studied from E=2.10 to 4.75 MeV by γ-ray spectroscopy using a C target with ultralow hydrogen contamination. The deduced astrophysical S(E)^{*} factor exhibits new resonances at E≤3.0 MeV, in particular, a strong re...
[Phys. Rev. Lett. 98, 122501] Published Wed Mar 21, 2007
Mechanism of Near-Threshold Production of the η Meson
Author(s): R. Czyżykiewicz et al.
Measurements of the analyzing power for the p[over →]p→ppη reaction have been performed at excess energies of Q=10 and 36 MeV. The determined analyzing power is essentially consistent with zero, implying dominance of the s wave at both excess energies. The angular dependence of the analyzing power,...
[Phys. Rev. Lett. 98, 122003] Published Wed Mar 21, 2007
Lifetime Difference and CP-Violating Phase in the B_{s}^{0} System
Author(s): V. M. Abazov et al. (D0 Collaboration)
From an analysis of the decay B_{s}^{0}→J/ψϕ, we obtain the width difference between the light and heavy mass eigenstates ΔΓ≡(Γ_{L}-Γ_{H})=0.17±0.09(stat)±0.02(syst) ps^{-1} and the CP-violating phase ϕ_{s}=-0.79±0.56(stat)_{-0.01}^{+0.14}(syst). Under the hypothesis of no CP violation (ϕ_{s}≡0), ...
[Phys. Rev. Lett. 98, 121801] Published Wed Mar 21, 2007
Dark Energy versus Modified Gravity
Author(s): M. Kunz and D. Sapone
There is now strong observational evidence that the expansion of the Universe is accelerating. The standard explanation invokes an unknown “dark energy” component. But such scenarios are faced with serious theoretical problems, which has led to increased interest in models where instead general rel...
[Phys. Rev. Lett. 98, 121301] Published Wed Mar 21, 2007
Cluster Simulations of Loop Models on Two-Dimensional Lattices
Author(s): Y. Deng, T. M. Garoni, W. Guo, H. W. J. Blöte, and A. D. Sokal
We develop cluster algorithms for a broad class of loop models on two-dimensional lattices, including several standard O(n) loop models at n≥1. We show that our algorithm has little or no critical slowing-down when 1≤n≤2. We use this algorithm to investigate the honeycomb-lattice O(n) loop model, f...
[Phys. Rev. Lett. 98, 120601] Published Wed Mar 21, 2007
Anomalous Polymer Sedimentation Far from Equilibrium
Author(s): X. Schlagberger and R. R. Netz
A single flexible polymer in strong sedimentation fields is investigated using hydrodynamic simulations and scaling arguments. For short chains and small fields compaction is observed. For elevated fields or long chains the chain stretches and the sedimentation coefficient decreases, in agreement w...
[Phys. Rev. Lett. 98, 128301] Published Tue Mar 20, 2007
Created by Jae-Yeol Hwang
Last modified : 4:14 am, 7 Nov 2006