Journal of Applied Physics: All Topics

Thermodynamics of the thermoelectric potential

Christophe Goupil
We derive the principal contributions to energy flux and entropy flux in a thermoelectric material using a force-flux description. Using the reduced current u=J/kappa[del]T of the coupled thermal and electrical flows, we introduce the so-called thermoelectric potential Talpha+1/u. We show that this ... [J. Appl. Phys. 106, 104907 (2009)] published Fri Nov 20, 2009.

First-principles simulations on bulk TaO and Cu/TaO/Pt heterojunction: Electronic structures and transport properties

Tingkun Gu, Zhongchang Wang, Tomofumi Tada, and Satoshi Watanabe
Electronic structures and transport properties of bulk TaO and Cu/TaO/Pt heterojunction have been studied from first principles. Of the two room-temperature phases of bulk TaO, beta-, and delta-TaO, our calculated results showed that the beta phase has much narrower band gap than the delta-TaO. For ... [J. Appl. Phys. 106, 103713 (2009)] published Fri Nov 20, 2009.

Photoinduced spin-polarized current in InSb-based structures

M. Frazier, J. G. Cates, J. A. Waugh, J. J. Heremans, M. B. Santos et al.
We demonstrate the observation of spin-polarized photocurrent in InSb films grown on GaAs and InP substrates and InSb quantum wells where a nonequilibrium spin population has been achieved by using circularly polarized radiation. The characteristics of our observations indicated that the circular ph ... [J. Appl. Phys. 106, 103513 (2009)] published Fri Nov 20, 2009.

Metal-semiconductor transition in epitaxial ZnO thin films

M. Nistor, F. Gherendi, N. B. Mandache, C. Hebert, J. Perriere et al.
We report on the formation and transport properties of ZnO thin films which are grown by pulsed-electron beam deposition under a low residual oxygen pressure (10 mbar). ZnO films presenting metallic conductivity at room temperature, and a metal-semiconductor transition at low temperature, were epit ... [J. Appl. Phys. 106, 103710 (2009)] published Fri Nov 20, 2009.

Flux pinning properties in BaMO (M=Zr,Sn) nanorod-introduced ErBaCuO films

Satoshi Awaji, Masafumi Namba, Kazuo Watnabe, Shun Ito, Eiji Aoyagi et al.
Flux pinning properties on the ErBaCaO films with the nanoscaled and columnar-shaped BaMO (BMO,M=Zr,Sn) precipitates, i.e., nanorods, were investigated systematically based on the microstructure, critical current density J and irreversibility field B properties in high magnetic fields. We found that ... [J. Appl. Phys. 106, 103915 (2009)] published Fri Nov 20, 2009.

Photoelectron spectroscopy study of systematically varied doping concentrations in an organic semiconductor layer using a molecular p-dopant

S. Olthof, W. Tress, R. Meerheim, B. Lussem, and K. Leo
We investigate the doping behavior of the strongly electron accepting molecule 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane coevaporated with the host molecule N,N,N,N-tetrakis(4-methoxyphenyl)-benzidine by photoemission spectroscopy and conductivity measurements. Using interface resolved me ... [J. Appl. Phys. 106, 103711 (2009)] published Fri Nov 20, 2009.

Optical spectroscopy and upconversion luminescence in Nd doped GaGeS glass

Vineet Kumar Rai, Cid B. de Araujo, Y. Ledemi, B. Bureau, M. Poulain et al.
Optical properties of a neodymium (Nd) doped glass having composition based on the (GaS)(GeS) system are reported. Transition probabilities, radiative lifetimes, and branching ratios related to Nd levels were determined. Frequency upconversion (UC) luminescence due to nonresonant excitation at 1064 ... [J. Appl. Phys. 106, 103512 (2009)] published Fri Nov 20, 2009.

Short- and long-range orders in FeCr: A Monte Carlo study

C. Pareige, C. Domain, and P. Olsson
Atomistic kinetic Monte Carlo simulations based on the two-band semiempirical cohesive model for FeCr have revealed a body centered tetragonal FeCr ordered compound at very low temperatures. Density functional theory calculations have shown that this structure is more stable than the FeCr compound r ... [J. Appl. Phys. 106, 104906 (2009)] published Fri Nov 20, 2009.

Theory of fundamental microwave absorption in sapphire (alpha-AlO)

Nicolas A. Shtin, Jose Mauricio Lopez Romero, and Eugene Prokhorov
An accurate model for intrinsic dielectric loss in sapphire (alpha-AlO) is presented. The proposed model is based on a theory of electromagnetic field absorption governed by multiphonon relaxation processes influenced by a finite lifetime of thermal phonons. Expressions for anisotropic sapphire diel ... [J. Appl. Phys. 106, 104115 (2009)] published Fri Nov 20, 2009.

A method for evaluating the ground state excitonic band gaps of strained InGaN/GaN quantum wells

T. K. Sharma and E. Towe
A simple method for calculating the ground state excitonic band gaps of strained wurtzite InGaN/GaN quantum wells (QWs) for the entire composition range is proposed. The modification of the electronic band structure due to strain becomes significant for high values of indium concentration. It is obs ... [J. Appl. Phys. 106, 104509 (2009)] published Fri Nov 20, 2009.

Charge order, dielectric response, and local structure of LaSrNiO system

M. Filippi, B. Kundys, S. Agrestini, W. Prellier, H. Oyanagi et al.
Charge ordering, dielectric permittivity, and local structure of LaSrNiO system have been explored by x-ray charge scattering, complex dielectric impedance spectroscopy, and extended x-ray absorption fine structure (EXAFS) measurements, made on the same single crystal sample. The local structure mea ... [J. Appl. Phys. 106, 104116 (2009)] published Fri Nov 20, 2009.

Enhancement of phosphorus activation in vacancy engineered thin silicon-on-insulator substrates

A. J. Smith, R. M. Gwilliam, V. Stolojan, A. P. Knights, P. G. Coleman et al.
The concentration of vacancy-type defects in a silicon-on-insulator substrate consisting of a 110 nm silicon overlayer and a 200 nm buried oxide has been quantified using variable energy positron annihilation spectroscopy following 300 keV Si ion implantation to a dose of 1.5 x 10 cm and subsequent ... [J. Appl. Phys. 106, 103514 (2009)] published Fri Nov 20, 2009.

Electrical control of magnetic remanent states in a magnetoelectric layered nanostructure

Tien-Kan Chung, Kin Wong, Scott Keller, Kang L. Wang, and Gregory P. Carman
We report experimental results on electrical control of magnetic remanent states (i.e., nanoscale remanent domain patterns) in a magnetoelectric layered nanostructure, Ni nanobar/lead zirconate titanate film. First, with application of different external magnetic fields as a baseline characterizatio ... [J. Appl. Phys. 106, 103914 (2009)] published Fri Nov 20, 2009.

Comparison of amorphous silicon photodiodes and photoconductors for detection of quantum dot biomolecular tags

A. C. Pimentel, D. M. F. Prazeres, V. Chu, and J. P. Conde
A comparative study of the performance of hydrogenated amorphous silicon photosensors based on two different device configurations for integration in a microarray platform for biomolecular detection is presented. A perpendicular contact p-i-n photodiode and a parallel contact intrinsic photoconducto ... [J. Appl. Phys. 106, 104904 (2009)] published Fri Nov 20, 2009.

Effect of the anisotropy distribution on the coercive field and switching field distribution of bit patterned media

P. Krone, D. Makarov, T. Schrefl, and M. Albrecht
We present a systematic study on the magnetization reversal in square arrays of magnetic nanostructures. To account for the unavoidable inhomogeneities of the magnetic properties due to, i.e., template preparation, a distribution of magnetic anisotropy values was taken into account. We show that the ... [J. Appl. Phys. 106, 103913 (2009)] published Fri Nov 20, 2009.

Simultaneous low-frequency noise characterization of gate and drain currents in AlGaN/GaN high electron mobility transistors

Hemant Rao and Gijs Bosman
Room temperature low frequency noise characteristics of gate and drain currents of an AlGaN/GaN high electron mobility transistor are reported. A Hooge parameter (alpha) ranging from 10 to 10 is extracted for drain current noise as a function of sheet carrier density. Gate current noise is simultane ... [J. Appl. Phys. 106, 103712 (2009)] published Fri Nov 20, 2009.

Quantifying fatigue generated in high strain rate cyclic loading of Norway spruce

Ari Salmi, Lauri Salminen, and Edward Haeggstrom
Papermaking, especially mechanical pulping, consumes much energy. To reduce this energy consumption one has to understand and exploit the phenomena present during the pulping. An important phenomenon to understand is wood fatigue. We quantitatively measure the fatigue generated during high strain ra ... [J. Appl. Phys. 106, 104905 (2009)] published Fri Nov 20, 2009.

Thermal stability and vibrational spectroscopy of NO shallow donor centers in silicon

Hans Christian Alt and Hans Edwin Wagner
NO-related shallow donors in nitrogen-doped Czochralski silicon have been studied by infrared spectroscopy. Quasithermal equilibrium states were established by long-term thermal annealing in the temperature range from 600 to 1000 degrees C. By quantitative analysis of the 1s-->2p far-infrared el ... [J. Appl. Phys. 106, 103511 (2009)] published Fri Nov 20, 2009.

Orientation dependence of ferroelectric behavior of BiFeO thin films

Jiagang Wu and John Wang
Multiferroic BiFeO (BFO) thin films with (111), (100), (110) preferred, and random orientations were deposited by radio frequency magnetron sputtering on SrRuO-buffered SrTiO(111), SrTiO(100), SrTiO(110), and Pt(111)/Ti/SiO/Si(100) substrates, respectively. The orientation dependences of ferroelectr ... [J. Appl. Phys. 106, 104111 (2009)] published Thu Nov 19, 2009.

Extension of the RosencwaigGershoFernelius photothermal deflection spectroscopy model to account for multiple reflections in epitaxial samples

I. C. W. Chan and M. Beaudoin
The Fernelius extension to the RosencwaigGersho theory for photothermal deflection spectroscopy (PDS) is modified to take into account multiple reflections and light trapping within a thin film-on-substrate system where both the thin film and the substrate can be absorbing. The extended model is use ... [J. Appl. Phys. 106, 103510 (2009)] published Thu Nov 19, 2009.

Adjustable resonance frequency and linewidth by Zr doping in Co thin films

Changjun Jiang, Desheng Xue, Dangwei Guo, and Xiaolong Fan
CoZr (40 nm) thin films with different Zr compositions were grown on silicon substrates by radio frequency magnetron sputtering. The coercivity decreased with an increase in the Zr composition. A uniaxial anisotropy existed in the CoZr films, and the anisotropy field of the films decreased from 55 t ... [J. Appl. Phys. 106, 103910 (2009)] published Thu Nov 19, 2009.

Effect of kinetic growth parameters on leakage current and ferroelectric behavior of BiFeO thin films

Vilas Shelke, V. N. Harshan, Sushma Kotru, and Arunava Gupta
Epitaxial BiFeO thin films have been grown on (100)-oriented SrTiO and Nb-doped SrTiO substrates using the pulsed laser deposition technique under identical thermodynamic and variable kinetic conditions. The variation of growth kinetics through laser fluence and pulse repetition rate had minimal eff ... [J. Appl. Phys. 106, 104114 (2009)] published Thu Nov 19, 2009.

Field dependence of the adiabatic temperature change in second order phase transition materials: Application to Gd

V. Franco, A. Conde, J. M. Romero-Enrique, Y. I. Spichkin, V. I. Zverev et al.
The field dependence of the adiabatic temperature change DeltaT of second order phase transition materials is studied, both theoretically and experimentally. Using scaling laws, it is demonstrated that, at the Curie temperature, the field dependence of DeltaT is characterized by H. Therefore, as the ... [J. Appl. Phys. 106, 103911 (2009)] published Thu Nov 19, 2009.

Degradation of Staphylococcus aureus bacteria by neutral oxygen atoms

U. Cvelbar, M. Mozetic, N. Hauptman, and M. Klanjsek-Gunde
The degradation of Staphylococcus aureus bacteria during treatment with neutral oxygen atoms was monitored by scanning electron microscopy. Experiments were performed in an afterglow chamber made from borosilicate glass. The source of oxygen atoms was remote inductively coupled radiofrequency oxygen ... [J. Appl. Phys. 106, 103303 (2009)] published Thu Nov 19, 2009.

Excitation dynamics in polymer-coated semiconductor quantum dots with integrated dye molecules: The role of reabsorption

Tobias Niebling, Feng Zhang, Zulqurnain Ali, Wolfgang J. Parak, and Wolfram Heimbrodt
Inorganic CdSe/ZnS core-shell quantum dots have been coated with amphiphilic polymers in order to enable their transfer to aqueous solutions. Additionally, ATTO-dye molecules have been embedded in the polymer shell. In this geometry ATTO dye acts as acceptor of the quantum dot donors' excitation. Th ... [J. Appl. Phys. 106, 104701 (2009)] published Thu Nov 19, 2009.

Decoupling two-step anodization in anodic aluminum oxide

Kwang Hong Lee and C. C. Wong
It is well known that ordered anodic aluminum oxide (AAO) can be fabricated by a two-step anodization process, but in the current approach, pore size and interpore spacing are coupled because the ordering mechanism is expected to be the same in both steps. Here, we demonstrate that, by using a diffe ... [J. Appl. Phys. 106, 104305 (2009)] published Thu Nov 19, 2009.

Zinc and oxygen vacancies in ZnO nanorods

A. Travlos, N. Boukos, C. Chandrinou, Ho-Sang Kwack, and Le Si Dang
Nominally undoped ZnO nanorods, which have been grown with intentionally incorporated large concentrations of zinc and oxygen vacancies, are studied with electron microscopy and photoluminescence spectroscopy at low temperature. Detailed photoluminescence studies reveal that the concentration of the ... [J. Appl. Phys. 106, 104307 (2009)] published Thu Nov 19, 2009.

A compact interferometric sensor design using three waveguide coupling

K. C. Vernon, D. E. Gomez, and T. J. Davis
The use of metal stripes for the guiding of plasmons is a well established technique for the infrared regime and has resulted in the development of a myriad of passive optical components and sensing devices. However, the plasmons suffer from large losses around sharp bends, making the compact design ... [J. Appl. Phys. 106, 104306 (2009)] published Thu Nov 19, 2009.

The Debye-like relaxation mechanism in poly(vinylidene fluoride-trifluoroethylene) ferroelectric polymers

P. F. Liu, P. Gemeiner, X. J. Meng, J. H. Chu, S. Geiger et al.
In this work we studied 65-nm-thick poly(vinylidene fluoride-trifluoroethylene) ferroelectric polymers films grown by LangmuirBlodgett onto silicon substrates. Three dielectric anomalies have been unambiguously evidenced. The high temperature one near 380 K corresponds to the ferroelectric-paraelect ... [J. Appl. Phys. 106, 104113 (2009)] published Thu Nov 19, 2009.

Computational study of thermocompression bonding of carbon nanotubes to metallic substrates

Xiaohui Song, Zhiyin Gan, Sheng Liu, Han Yan, and Qiang Lv
Thermocompression bonding of carbon nanotubes (CNTs) to metallic substrates is studied using molecular dynamics. The interaction of the CNT and the metal cluster at high temperature is investigated first. For the diffusion bonding process, the effects of temperature and external pressure are examine ... [J. Appl. Phys. 106, 104308 (2009)] published Thu Nov 19, 2009.

Significant suppression of space charge injection into linear low density polyethylene by surface oxyfluorination

Zhenlian An, Chen Xie, Yue Jiang, Feihu Zheng, and Yewen Zhang
Surface oxyfluorination of linear low density polyethylene (LLDPE) was performed to suppress space charge injection and accumulation under direct current high voltage. Significant suppression effect that there is almost no space charge inside LLDPE was obtained, as observed by space charge measureme ... [J. Appl. Phys. 106, 104112 (2009)] published Thu Nov 19, 2009.

Size effect on magnetic and ferroelectric properties in BiFeO multiferroic ceramics

Z. M. Tian, S. L. Yuan, X. L. Wang, X. F. Zheng, S. Y. Yin et al.
Magnetic and ferroelectric properties are investigated for the polycrystalline BiFeO ceramics with different grain sizes (602000 nm) synthesized by a modified Pechini method. It shows that magnetic and ferroelectric properties are strongly dependent on the grain size. For the 60 nm samples, the magn ... [J. Appl. Phys. 106, 103912 (2009)] published Thu Nov 19, 2009.

The structural parameter optimization of interdigital transducer in single electron transport devices

Li Song, Hui Yuan, Chuanyu Zhang, Ling Li, Chuan Lu et al.
We investigate the influence of the interdigital transducer (IDT) structure on the amplitude of the surface acoustic wave (SAW) in a SAW device. The SAW amplitude at the entrance of the quantum point contact (QPC) is obtained by using coupling-of-modes theory and p-matrix method. The calculated resu ... [J. Appl. Phys. 106, 104508 (2009)] published Thu Nov 19, 2009.

Effect of azimuthally asymmetric reactor components on a parallel plate capacitively coupled plasma

Jason A. Kenney, Shahid Rauf, and Ken Collins
A three-dimensional fluid plasma model is used to investigate the impact of azimuthally asymmetric reactor components on spatial characteristics of parallel plate capacitively coupled plasmas. We consider three scenarios: high frequency (13.56 MHz) argon discharges with, separately, an off-axis circ ... [J. Appl. Phys. 106, 103302 (2009)] published Thu Nov 19, 2009.

Dielectric response of tantalum oxide subject to induced ion bombardment during oblique sputter deposition

S. C. Barron, M. M. Noginov, D. Werder, L. F. Schneemeyer, and R. B. van Dover
We describe the deposition of insulating tantalum oxide thin films under conditions of controlled ion bombardment, which can be achieved using reactive sputtering on 90 degrees off-axis substrates with an applied substrate bias. Capacitive measurements of TaO deposited on unbiased off-axis substrat ... [J. Appl. Phys. 106, 104110 (2009)] published Wed Nov 18, 2009.

Strength of lithium fluoride under shockless compression to 114 GPa

T. Ao, M. D. Knudson, J. R. Asay, and J.-P. Davis
A magnetic loading technique was used to ramp load single-crystal [100] lithium fluoride specimens to peak stresses of 5114 GPa. Wave analysis of in situ particle velocity profiles was used to estimate the compressive strength of LiF at peak stress. It was found that the strength increased with peak ... [J. Appl. Phys. 106, 103507 (2009)] published Wed Nov 18, 2009.

GeSbTe thin films deposited by pulsed laser: An ellipsometry and Raman scattering spectroscopy study

P. Nemec, A. Moreac, V. Nazabal, M. Pavlista, J. Prikryl et al.
Pulsed laser (532 nm) deposited GeSbTe thin films were investigated by means of spectroscopic ellipsometry and Raman scattering spectroscopy. TaucLorentz and CodyLorentz models were employed for the evaluation of optical functions of thin films in as-deposited (amorphous) and crystalline (cubic) pha ... [J. Appl. Phys. 106, 103509 (2009)] published Wed Nov 18, 2009.

Highly mismatched crystalline and amorphous GaNAs alloys in the whole composition range

K. M. Yu, S. V. Novikov, R. Broesler, I. N. Demchenko, J. D. Denlinger et al.
Alloying is a commonly accepted method to tailor properties of semiconductor materials for specific applications. Only a limited number of semiconductor alloys can be easily synthesized in the full composition range. Such alloys are, in general, formed of component elements that are well matched in ... [J. Appl. Phys. 106, 103709 (2009)] published Wed Nov 18, 2009.

Enhancement of light transmission by coupling to surface plasmon polaritons of a layer-plus-islands silver layer

Pangpang Wang, Dongyan Zhang, Dong Hun Kim, Zhiyong Qiu, Lumei Gao et al.
Enhanced light transmission through coupling incident light with surface plasmon polaritons (SPPs) on a layer-plus-islands nanostructure Ag layer, surrounded by symmetric ZnO dielectrics (ZnO/Ag/ZnO), was investigated. The couple and decouple processes at ZnO/Ag and Ag/ZnO grating interfaces were co ... [J. Appl. Phys. 106, 103104 (2009)] published Wed Nov 18, 2009.

Energy transfer rates and population inversion of I excited state of Er investigated by means of numerical solutions of the rate equations system in Er:LiYF crystal

Laercio Gomes, Andre Felipe Henriques Librantz, Fabio Henrique Jagosich, Wonder Alexandre Luz Alves, Izilda Marcia Ranieri et al.
In this work, we present the spectroscopic properties of LiYF (YLF) single crystals activated by high doping of erbium ions. The most important processes that lead to the up-conversion erbium emissions in the infrared region were identified. A time-resolved luminescence spectroscopy technique was em ... [J. Appl. Phys. 106, 103508 (2009)] published Wed Nov 18, 2009.

Schottky's conjecture on multiplication of field enhancement factors

Ryan Miller, Y. Y. Lau, and John H. Booske
Of great interest to high power microwave, millimeter wave to terahertz sources, x-ray tubes, electrons guns, etc., is the electric field enhancement obtained from sharp emitting structures fabricated by various microfabrication methods. In this paper, we use conformal mapping to investigate the fie ... [J. Appl. Phys. 106, 104903 (2009)] published Wed Nov 18, 2009.

Coupled optoelectronic simulation of organic bulk-heterojunction solar cells: Parameter extraction and sensitivity analysis

R. Hausermann, E. Knapp, M. Moos, N. A. Reinke, T. Flatz et al.
A comprehensive optoelectronic device model for organic bulk-heterojunction solar cells is presented. First the optical incoupling into a multilayer stack is calculated. From the photon absorption profile a charge transfer exciton profile is derived. In this study we consider the OnsagerBraun mechan ... [J. Appl. Phys. 106, 104507 (2009)] published Wed Nov 18, 2009.

Comparison between hot spot modeling and measurement of a superconducting hot electron bolometer mixer at submillimeter wavelengths

Wei Miao, Yan Delorme, Alexandre Feret, Rolland Lefevre, Benoit Lecomte et al.
This paper presents the modeling and measurement of a quasioptical niobium nitride superconducting hot electron bolometer mixer at submillimeter wavelengths. The modeling is performed with a distributed hot spot model which is based on solving a heat balance equation for electron temperature along t ... [J. Appl. Phys. 106, 103909 (2009)] published Wed Nov 18, 2009.

Influence of C morphology on high-order harmonic generation enhancement in fullerene-containing plasma

R. A. Ganeev, H. Singhal, P. A. Naik, J. A. Chakera, A. K. Srivastava et al.
The morphologies of the fullerene targets and the ablated fullerenes to determine the optimal conditions of excitation of the C-containing targets have been analyzed. The optimization of fullerene-containing plasma conditions allowed the enhanced harmonic generation in these plasmas using laser radi ... [J. Appl. Phys. 106, 103103 (2009)] published Wed Nov 18, 2009.

Time-dependent analysis of low V program operation in double-gate SONOS memories by full-band Monte Carlo simulation

G. Giusi, G. Iannaccone, and U. Ravaioli
In this paper, we investigate warm electron injection (WEI) as a mechanism for NOR programming of double-gate SONOS memories through two dimensional (2D) full-band Monte Carlo simulations. WEI is characterized by an applied V smaller than 3.15 V, so that electrons cannot easily accumulate a kinetic ... [J. Appl. Phys. 106, 104506 (2009)] published Tue Nov 17, 2009.

Large radiation fields from nonlocal interaction between terahertz waves and quantum wells with an applied electric field

Guanghui Wang and Qi Guo
The effects of pump intensities and applied electric fields on radiation fields excited by the nonlocal interaction between terahertz waves and AlGaAs/GaAs quantum wells (QWs) are investigated. The numerical results show the resonant radiation fields are very large in the confinement direction, and ... [J. Appl. Phys. 106, 103506 (2009)] published Tue Nov 17, 2009.

Determining the size distribution of magnetic nanoparticles based on analysis of magnetization curves

Su-Peng Yu, Yi-Hsien Liu, An-Cheng Sun, and Jen-Hwa Hsu
This study develops a direct scheme that is based on the magnetization curve of magnetic nanoparticles in the medium-field region above the blocking temperature to extract information on the size of particles and the uniformity thereof. The magnetization curve was fitted with a computer software tha ... [J. Appl. Phys. 106, 103905 (2009)] published Tue Nov 17, 2009.

Arsenic antisite defects in p-GaAs grown by metal-organic chemical-vapor deposition and the EL2 defect

Nazir A. Naz, Umar S. Qurashi, and M. Zafar Iqbal
Epitaxial layers of p-GaAs grown on p-GaAs substrates by low-pressure metal organic chemical vapor deposition have been investigated using deep level transient spectroscopy (DLTS). One dominant peak and other relatively small peak, corresponding to deep levels at E+0.55 eV and E+0.96 (low field ene ... [J. Appl. Phys. 106, 103704 (2009)] published Tue Nov 17, 2009.

Flexure mode flexoelectric piezoelectric composites

Baojin Chu, Wenyi Zhu, Nan Li, and L. Eric Cross
We present a flexure mode composite design to generate steep transverse strain gradient to exploit large flexoelectric coefficient [mu] of (Ba,Sr)TiO (BST) ceramics. Very strong direct piezoelectric effect was observed in composites due to the flexoelectricity. In a single unit composite, sharp low ... [J. Appl. Phys. 106, 104109 (2009)] published Tue Nov 17, 2009.

Scanning capacitance microscopy studies of unintentional doping in epitaxial lateral overgrowth GaN

J. Sumner, R. A. Oliver, M. J. Kappers, and C. J. Humphreys
Four samples were grown by epitaxial lateral overgrowth (ELOG) using different magnesium precursor fluxes during the coalescence stage. These samples were studied in cross section using scanning capacitance microscopy and scanning electron microscopy. The resulting images revealed the existence of s ... [J. Appl. Phys. 106, 104503 (2009)] published Tue Nov 17, 2009.

Asymmetric magnetization reversal process in Co nanohill arrays

W. O. Rosa, L. Martinez, M. Jaafar, A. aAsenjo, and M. Vazquez
Co thin films deposited by sputtering onto nanostructured polymer [poly(methyl methacrylate)] were prepared following replica-antireplica process based on porous alumina membrane. In addition, different capping layers were deposited onto Co nanohills. Morphological and compositional analysis was per ... [J. Appl. Phys. 106, 103906 (2009)] published Tue Nov 17, 2009.

Leakage mechanism in flat seals

F. Bottiglione, G. Carbone, L. Mangialardi, and G. Mantriota
We present a theoretical approach to estimate the fluid leakage in flat seals. The approach is based on the analogy between the seal-substrate interface and a porous medium. We assume that the interface is constituted of a random distribution of noncontact patches (the pores) and small but numerous ... [J. Appl. Phys. 106, 104902 (2009)] published Tue Nov 17, 2009.

Origin(s) of the apparent high permittivity in CaCuTiO ceramics: clarification on the contributions from internal barrier layer capacitor and sample-electrode contact effects

Ming Li, Zhijian Shen, Mats Nygren, Antonio Feteira, Derek C. Sinclair et al.
CaCuTiO ceramics with a range of resistivities have been prepared using both conventional sintering and spark plasma sintering. For all cases, the high effective permittivity is associated primarily with an internal barrier layer capacitor mechanism. Additional polarization associated with the elect ... [J. Appl. Phys. 106, 104106 (2009)] published Tue Nov 17, 2009.

Study of acoustic wave behavior in silicon-based one-dimensional phononic-crystal plates using harmony response analysis

Xuefeng Zhu (祝雪丰), Tao Xu (徐涛), Shengchun Liu (刘盛春), and Jianchun Cheng (程建春)
We promote an efficient method named harmony response analysis (HRA) as a comparison with transient response analysis and supercell plane wave expansion (supercell PWE) to study the behavior of Lamb wave in silicon-based one-dimensional composite plates. To implement HRA for dealing with Lamb waves ... [J. Appl. Phys. 106, 104901 (2009)] published Tue Nov 17, 2009.

The effect of MgO barrier on the structure and magnetic properties of CoMnSi films on n-Si(100) substrates

M. A. I. Nahid, M. Oogane, H. Naganuma, and Y. Ando
We investigated the structure and magnetic properties of CoMnSi/MgO/n-Si(100) films with the goal of achieving efficient spin injection. The CoMnSi films were fabricated by dc sputtering and post annealed at 400 degrees C for 1 h. They were oriented along the direction with a MgO barrier layer. A ... [J. Appl. Phys. 106, 103907 (2009)] published Tue Nov 17, 2009.

Alpha particle detection with GaN Schottky diodes

A. Y. Polyakov, N. B. Smirnov, A. V. Govorkov, A. V. Markov, E. A. Kozhukhova et al.
Ni/GaN Schottky diode radiation detectors were fabricated on 3-[mu]m-thick unintentionally doped n-GaN films grown by molecular beam epitaxy (MBE) and metal organic chemical vapor deposition (MOCVD) and on 12-[mu]m-thick undoped n-GaN layers prepared by epitaxial lateral overgrowth (ELOG). The rever ... [J. Appl. Phys. 106, 103708 (2009)] published Tue Nov 17, 2009.

Electron transport in quantum antidots made of four-terminal graphene ribbons

C. Ritter, M. Pacheco, P. Orellana, and A. Latge
Electronic and transport properties of two- and four-terminal graphene nanoribbons are studied taking into account different configurations of quantum antidot potentials, designed at a central conductor. Local density of states maps the electronic distribution changes induced by the antidot potentia ... [J. Appl. Phys. 106, 104303 (2009)] published Tue Nov 17, 2009.

Vibration analysis of nanoplates under uniaxial prestressed conditions via nonlocal elasticity

T. Murmu and S. C. Pradhan
In this article, nonlocal elasticity theory is applied to investigate the vibration response of nanoplates under uniaxially prestressed conditions. Nonlocal elasticity theory takes into account the small-size effects when dealing with nanostructures. Nonlocal governing equations of the prestressed n ... [J. Appl. Phys. 106, 104301 (2009)] published Tue Nov 17, 2009.

Coexistence of magnetic and ferroelectric behaviors of pyrochlore HoTiO

X. W. Dong, K. F. Wang, S. J. Luo, J. G. Wan, and J.M. Liu
Rare-earth titanate cubic pyrochlore HoTiO ceramics are prepared by the standard solid state reaction. The magnetic, dielectric, and ferroelectric behaviors are measured in order to investigate the multiferroic behaviors of HoTiO. Upon the gradual spin ordering sequence with decreasing temperature, ... [J. Appl. Phys. 106, 104101 (2009)] published Tue Nov 17, 2009.

Persistent photocurrent and decay studies in CdS nanorods thin films

Gouri Sankar Paul and Pratima Agarwal
Structural and electrical transport properties of thin films of CdS nanorods synthesized by solvothermal process are studied through x-ray diffraction, scanning electron microscopy, transmission electron microscopy, activation energy measurements, and decay of photoconductivity. The films show therm ... [J. Appl. Phys. 106, 103705 (2009)] published Tue Nov 17, 2009.

Magnetic transitions in alpha-FeO nanowires

C. Diaz-Guerra, L. Perez, J. Piqueras, and M. F. Chioncel
Magnetic transitions in single-crystal alpha-FeO (hematite) nanowires, grown by thermal oxidation of iron powder, have been studied in the range of 51023 K with a superconducting quantum interference device below room temperature and with a vibrating sample magnetometer at higher temperatures. The ... [J. Appl. Phys. 106, 104302 (2009)] published Tue Nov 17, 2009.

Dielectric, ferroelectric, and piezoelectric behaviors of AgNbOKNbO solid solution

Desheng Fu, Mitsuru Itoh, and Shin-ya Koshihara
Phase evolution in the (AgK)NbO (AKN) solid solution was investigated by x-ray diffraction, dielectric, and ferroelectric measurements. At room temperature, there are three phase boundaries at x[approximate]0.07, x[approximate]0.20, and x[approximate]0.8. When x

A quality map of transfer printing

Matthew B. Tucker, D. R. Hines, and Teng Li
Transfer printing is a nanofabrication technique that involves an assembly process by which a printable layer can be transferred from a transfer substrate to a device substrate. Future application of transfer printing toward a roll-to-roll printing process of flexible devices hinges upon the underst ... [J. Appl. Phys. 106, 103504 (2009)] published Tue Nov 17, 2009.

Monte Carlo simulation of charge transport in amorphous chalcogenides

Fabrizio Buscemi, Enrico Piccinini, Rossella Brunetti, Massimo Rudan, and Carlo Jacoboni
The most peculiar feature exhibited by the I(V) characteristics of amorphous-chalcogenide materials is undoubtedly its S-shaped behavior. This type of characteristics is very important for the technological application, e.g., in the field of nanoscale solid-state memories. In this paper we give a mi ... [J. Appl. Phys. 106, 103706 (2009)] published Tue Nov 17, 2009.

Spectroscopic investigation of wave driven microwave plasmas

R. Wijtvliet, E. Felizardo, E. Tatarova, F. M. Dias, C. M. Ferreira et al.
Large H atom line broadening was found throughout the volume of surface wave generated HeH and H microwave plasmas at low pressures. The measured Doppler temperatures corresponding to the H, H, H, H, and H line profiles were found to be higher than the rotational temperature of the hydrogen molecula ... [J. Appl. Phys. 106, 103301 (2009)] published Tue Nov 17, 2009.

Phenomenological classification of stress-induced leakage current and time-dependent dielectric breakdown mechanism

Hiroshi Miyazaki, Daisuke Kodama, and Naohito Suzumura
The time-dependent dielectric breakdown (TDDB) of Cu damascene interconnects was investigated, noting the time variations in stress-induced leakage current. Copper interconnects normally have symmetric current-voltage curves, which suggests that defects are distributed symmetrically between two Cu l ... [J. Appl. Phys. 106, 104103 (2009)] published Tue Nov 17, 2009.

SnO nanoparticles embedded in silica by ion implantation followed by thermal oxidation

M. A. Tagliente, V. Bello, G. Pellegrini, G. Mattei, P. Mazzoldi et al.
Nanoparticles of tin dioxide embedded in silica matrix were synthesized by ion implanting a Sn ion beam in a silica slide and by annealing in oxidizing atmosphere at 800 degrees C. A detailed structural and optical characterization was performed by using glancing incidence x-ray diffraction, transm ... [J. Appl. Phys. 106, 104304 (2009)] published Tue Nov 17, 2009.

Effects of oxygen vacancy on ferroelectricity in Ba(FeNb)O thin films grown by pulsed laser deposition

Wei Zhang, Lei Li, and Xiang Ming Chen
Well-crystallized Ba(FeNb)O thin films were grown on Pt/TiO/SiO/Si substrates in various oxygen pressures at 550 degrees C by pulsed laser deposition. X-ray diffraction analysis revealed that the thin films had a single phase of perovskite structure. The lattice constants of thin films increased ob ... [J. Appl. Phys. 106, 104108 (2009)] published Tue Nov 17, 2009.

Nonhysteretic behavior inside the hysteresis loop of VO and its possible application in infrared imaging

M. Gurvitch, S. Luryi, A. Polyakov, and A. Shabalov
In the resistive phase transition in VO, temperature excursions taken from points on the major hysteresis loop produce minor loops. For sufficiently small excursions these minor loops degenerate into single-valued, nonhysteretic branches (NHBs) linear in log(rho) versus T and having essentially the ... [J. Appl. Phys. 106, 104504 (2009)] published Tue Nov 17, 2009.

Pressure-induced spin reorientation in LaSr(MnRu)O (y=0 and 0.075) single crystals

K. Mydeen, S. Arumugam, P. Mandal, A. Murugeswari, C. Sekar et al.
The effect of hydrostatic pressure (P) and external magnetic field on the c-axis resistivity (rho) and in-plane ac susceptibility (chi) of LaSr(MnRu)O (y=0 and 0.075) single crystals have been investigated. The ferromagnetic transition temperature (T) increases, while the conductivity decreases, wit ... [J. Appl. Phys. 106, 103908 (2009)] published Tue Nov 17, 2009.

Nonuniversal percolation exponents and broadband dielectric relaxation in carbon black loaded epoxy composites

S. El Bouazzaoui, A. Droussi, M. E. Achour, and C. Brosseau
In this study we present measurements and data analysis of the dielectric relaxation in carbon black (CB) loaded epoxy composites over a wide range of CB concentration (below and above the percolation threshold) and a broad range of frequency (1801.5 x 10 Hz). We show that our data are in conflict ... [J. Appl. Phys. 106, 104107 (2009)] published Tue Nov 17, 2009.

Light absorption in silicon quantum dots embedded in silica

S. Mirabella, R. Agosta, G. Franzo, I. Crupi, M. Miritello et al.
The photon absorption in Si quantum dots (QDs) embedded in SiO has been systematically investigated by varying several parameters of the QD synthesis. Plasma-enhanced chemical vapor deposition (PECVD) or magnetron cosputtering (MS) have been used to deposit, upon quartz substrates, single layer, or ... [J. Appl. Phys. 106, 103505 (2009)] published Tue Nov 17, 2009.

Dielectric properties of single crystalline PrO(111)/Si(111) heterostructures: Amorphous interface and electrical instabilities

O. Seifarth, Ch. Walczyk, G. Lupina, J. Dabrowski, P. Zaumseil et al.
Single crystalline PrO(111)/Si(111) heterostructures are flexible buffers for global Ge integration on Si. A combined materials scienceelectrical characterization is carried out to study the influence of postdeposition annealing in 1 bar oxygen at 300600 degrees C on the dielectric properties of Pr ... [J. Appl. Phys. 106, 104105 (2009)] published Tue Nov 17, 2009.

Current on/off ratio enhancement of field effect transistors with bundled carbon nanotubes

Y. Feng, K. Lee, H. Farhat, and J. Kong
This work examines the enhancement of current on/off ratio in field effect transistor devices with bundled single-walled carbon nanotubes (CNTs) by incorporating a substrate etching step before the electrical cutting for metallic CNT elimination. The etching step prevents the damaging of the semicon ... [J. Appl. Phys. 106, 104505 (2009)] published Tue Nov 17, 2009.

An impedance spectroscopic investigation of the electrical properties of delta-doped diamond structures

Niall Tumilty, Joseph Welch, Richard Lang, Christopher Wort, Richard Balmer et al.
Impedance spectroscopy has been used to investigate the conductivity displayed by diamond doped with boron in an intrinsic-delta-layer-intrinsic multilayer system with differing delta-layer thicknesses. Carrier transport within 5 nm delta-layer structures is complex, being dominated by conduction in ... [J. Appl. Phys. 106, 103707 (2009)] published Tue Nov 17, 2009.

Threshold fields in the dc bias dependence of dielectric responses of relaxor ferroelectric terpolymer films

X. J. Meng, B. Dkhil, P. F. Liu, J. L. Wang, J. L. Sun et al.
The dc bias dependence of dielectric properties has been investigated for poly (vinylindene fluoride-trifluoroethylene-chlorofluoroethylene) relaxor terpolymer films. The frequency dependence of the temperature of the permittivity maximum, T, was analyzed using the VogelFulcher (VF) relation. Two th ... [J. Appl. Phys. 106, 104102 (2009)] published Tue Nov 17, 2009.

Enhanced response of current-driven coupled quantum wells

Antonios Balassis and Godfrey Gumbs
We have investigated the conditions necessary to achieve stronger Cherenkov-like instability of plasma waves leading to emission in the terahertz regime for semiconductor quantum wells. The surface response function is calculated for a bilayer two-dimensional electron gas (2DEG) system in the presen ... [J. Appl. Phys. 106, 103102 (2009)] published Tue Nov 17, 2009.

First order reversal curve diagrams of perpendicular magnetic anisotropy films

Jinhua Yin, Hongwei Zhang, Fengxia Hu, Baogen Shen, and L. Q. Pan
The exchange coupling and magnetic properties distributions in Co/Pd multilayer perpendicular magnetic anisotropy films with different magnetic properties are investigated using the experimental first order reversal curve (FORC) diagram with assistance of LandauLifshitzGilbert simulation. The simula ... [J. Appl. Phys. 106, 103901 (2009)] published Mon Nov 16, 2009.

In situ x-ray diffraction investigation on early stages of oxidation at 900 degrees C of gamma-TiAl dipped in a phosphoric acid solution

S. Y. Brou, P. O. Renault, C. Huvier, J. L. Grosseau-Poussard, and G. Bonnet
The short term oxidation behavior of gamma-TiAl treated in low-concentration phosphoric acid solution has been investigated at 900 degrees C in air. A pyrophosphate film isomorphous to TiPO is formed during the initial thermal treatment step and is responsible for a subsequent large reduction in th ... [J. Appl. Phys. 106, 103502 (2009)] published Mon Nov 16, 2009.

Effect of annealing on charge transfer in Ge nanocrystal based nonvolatile memory structure

M. Yang, T. P. Chen, Z. Liu, J. I. Wong, W. L. Zhang et al.
Ge nanocrystals (nc-Ge) embedded in the gate oxide of the nonvolatile memory structure were synthesized by Ge ion implantation followed by thermal annealing at 800 degrees C for various durations. Large changes in the structural and chemical properties of the Ge-implanted oxide have been observed, ... [J. Appl. Phys. 106, 103701 (2009)] published Mon Nov 16, 2009.

Nanocrystalline metastable 2/17 and 1/12 precursors: A promising class of hard magnetic materials

L. Bessais, C. Djega-Mariadassou, H. Lassri, and N. Mliki
We present a general structure model relative to the metastable P6/mmm precursors of the I4/mmm RFeTi (R=Pr,Sm) and R[overline 3]m Sm(Fe,M) (M=Ga,Si) equilibrium phases. This model is based on the description of the binary RM compounds (s=vacancy rate, M=metal). The Rietveld analysis leads to stoi ... [J. Appl. Phys. 106, 103904 (2009)] published Mon Nov 16, 2009.

Energy relaxation probed by weak antilocalization measurements in GaN heterostructures

H. Cheng, N. Biyikli, J. Xie, C. Kurdak, and H. Morkoc
Energy relaxation and electron-phonon (e-p) interaction are investigated in wurtzite AlGaN/AlN/GaN and AlInN/AlN/GaN heterostructures with polarization induced two-dimensional electron gases in the BlochGruneisen regime. Weak antilocalization (WAL) and Shubnikovde Haas measurements were performed on ... [J. Appl. Phys. 106, 103702 (2009)] published Mon Nov 16, 2009.

Extended x-ray absorption fine structure study of arsenic in HgCdTe: p-type doping linked to nonsubstitutional As incorporation in an unknown AsHg structure

X. Biquard, I. Alliot, and P. Ballet
An extended x-ray absorption fine structure (EXAFS) investigation has been carried out on arsenic-doped HgCdTe samples. The incorporation of atomic arsenic has been achieved using a nonconventional radio-frequency plasma source in a molecular beam epitaxy reactor. Two samples from the same epitaxial ... [J. Appl. Phys. 106, 103501 (2009)] published Mon Nov 16, 2009.

Resonance terahertz detection in ungated two-dimensional electron gas

M. V. Cheremisin
The response of an ungated two-dimensional electron gas to an external electromagnetic excitation is analyzed. The possibility of creating a single-mode resonance detector operating in the terahertz frequency range is demonstrated. ... [J. Appl. Phys. 106, 104501 (2009)] published Mon Nov 16, 2009.

Tunable propagation of light through a coupled-bent dielectric-loaded plasmonic waveguides

Hong-Son Chu, Wei-Bin Ewe, and Er-Ping Li
We numerically show that it is easy to tune, both passively and actively, the transmission power delivered at different output ports of two coupled-bent dielectric-loaded plasmonic waveguides by varying the gap distance and refractive index of driven material between two dielectric stripes. We also ... [J. Appl. Phys. 106, 106101 (2009)] published Mon Nov 16, 2009.

Analytical model of the quasistatic mechanical behavior of galvanic piezoelectric microelectromechanical system switches

Olaf Wunnicke
An analytical model of the quasistatic behavior of galvanic piezoelectric microelectromechanical system (MEMS) switches is described. The model is based on the EulerBernoulli beam equation. Two geometries often used in galvanic switches are investigated: the single clamped cantilever (SCC) and the d ... [J. Appl. Phys. 106, 104502 (2009)] published Mon Nov 16, 2009.

Near coalescent submicron polycrystalline diamond films deposited on silicon: Hydrogen bonding and thermal enhanced carbide formation

A. Stacey, Sh. Michaelson, J. Orwa, S. Rubanov, S. Prawer et al.
The influence of high temperature annealing up to 1200 degrees C in vacuum on ~100 nm nearly continuous thick diamond films consisting of 3050 nm crystallites, deposited onto silicon substrates is reported. The hydrogen bonding and phase composition of the films were studied with Raman spectroscop ... [J. Appl. Phys. 106, 103503 (2009)] published Mon Nov 16, 2009.

Angular dependence of magnetic properties in Ni nanowire arrays

R. Lavin, J. C. Denardin, J. Escrig, D. Altbir, A. Cortes et al.
The angular dependence of the remanence and coercivity of Ni nanowire arrays produced inside the pores of anodic alumina membranes has been studied. By comparing our analytical calculations with our measurements, we conclude that the magnetization reversal in this array is driven by means of the nuc ... [J. Appl. Phys. 106, 103903 (2009)] published Mon Nov 16, 2009.

Mechanisms of the ultrafast magnetization switching in bistable amorphous microwires

M. Ipatov, V. Zhukova, A. K. Zvezdin, and A. Zhukov
Two magnetization reversal regimes were found in magnetically bistable Fe-rich microwires. The first one, exhibiting an almost linear dependence of the domain wall velocity v on magnetic field H reaching 1.7 km/s, is related to single DW propagation. The second essentially nonlinear regime is observ ... [J. Appl. Phys. 106, 103902 (2009)] published Mon Nov 16, 2009.

Enhanced thermoelectric performance by the combination of alloying and doping in TiCoSb-based half-Heusler compounds

Pengfei Qiu, Xiangyang Huang, Xihong Chen, and Lidong Chen
TiCoSb-based half-Heusler compounds have been prepared and their thermoelectric properties are studied. By isoelectronic alloying on the Ti site with Zr, although both the thermal conductivity and electrical conductivity are suppressed, the Seebeck coefficient is improved remarkably with a highest v ... [J. Appl. Phys. 106, 103703 (2009)] published Mon Nov 16, 2009.

Surface plasmon resonance-based gas sensor with chalcogenide glass and bimetallic alloy nanoparticle layer

Anuj K Sharma and Rajan Jha
A theoretical model for a gas sensor based on chalcogenide prism and surface plasmon resonance is proposed. The metal layer consists of AgAu alloy nanoparticles. The chalcogenide prism is made of sulfide glass GeGaSbS, commonly known as 2S2G. The angular interrogation method is used to analyze the s ... [J. Appl. Phys. 106, 103101 (2009)] published Mon Nov 16, 2009.

Atomic and electronic structure of the YBaCuO/SrTiO interface from first principles

Zhongchang Wang, Susumu Tsukimoto, Mitsuhiro Saito, and Yuichi Ikuhara
The atomic structure, adhesion energy, and bonding nature of the YBaCuO(001)/SrTiO(001) interface are systematically investigated from first principles. A total of 48 candidate interface geometries, which involve two SrTiO terminations, six YBaCuO terminations, and four highly symmetric stacking seq ... [J. Appl. Phys. 106, 093714 (2009)] published Fri Nov 13, 2009.

Dynamics of a rigid plate impacting a glass plate: A one dimensional analysis considering failure-wave propagation

Sergey L. Lopatnikov, Bazle A. Gama, Travis A. Bogetti, and John W. Gillespie, Jr.
Dynamics of a rigid plate impacting a glass plate is presented considering failure-wave and shock-wave propagations in the target material in addition to an elastic precursor. A generalized one dimensional theoretical failure-shock-elastic (FSE) model is developed and later simplified to study diffe ... [J. Appl. Phys. 106, 093521 (2009)] published Fri Nov 13, 2009.

Photoluminescence of an AlGaAs/GaAs multiple quantum well in the temperature range from 5 to 400 K

Giang T. Dang, Hiroshi Kanbe, and Masafumi Taniwaki
Photoluminescence (PL) of an unintentionally doped AlGaAs/GaAs multiple quantum well (MQW) has been measured at temperatures from 5 to 400 K. It was found that the ratio of the intensity of the n=1 electron-light hole transition (1e-1lh) to that of the n=1 electron-heavy hole transition (1e-1hh) can ... [J. Appl. Phys. 106, 093523 (2009)] published Fri Nov 13, 2009.

Direct measurement of spatial modes of a microcantilever from thermal noise

Pierdomenico Paolino, Bruno Tiribilli, and Ludovic Bellon
Measurements of the deflection induced by thermal noise have been performed on a rectangular atomic force microscope cantilever in air. The detection method, based on polarization interferometry, can achieve a resolution of 10 m/sqrt(Hz) in the frequency range 1800 kHz. The focused beam from the in ... [J. Appl. Phys. 106, 094313 (2009)] published Fri Nov 13, 2009.

A complex x-ray structure characterization of Ge thin film heterostructures integrated on Si(001) by aspect ratio trapping and epitaxial lateral overgrowth selective chemical vapor deposition techniques

P. Zaumseil, T. Schroeder, Ji-Soo Park, J. G. Fiorenza, and A. Lochtefeld
The development of Ge thin film substrates with low defect densities is of interest for future microelectronics as well as photovoltaics. This paper presents a complex x-ray characterization of Ge heterostructures, which were integrated on patterned Si(001) substrates using aspect ratio trapping (AR ... [J. Appl. Phys. 106, 093524 (2009)] published Fri Nov 13, 2009.

Mid-infrared emission from InAs quantum dots, wells, and dots on well nanostructures grown on InP (100) by metal organic vapor phase epitaxy

Junji Kotani, Peter J. van Veldhoven, and Richard Notzel
A detailed analysis to extend the emission wavelength of InAs/InP nanostructures is presented employing InAs quantum dots (QDs), InAs quantum wells (QWs), and a combination of InAs QDs and QWs grown on InGaAsP/InP (100) by metal organic vapor phase epitaxy. First the optimized growth conditions of I ... [J. Appl. Phys. 106, 093112 (2009)] published Fri Nov 13, 2009.

Relationship between oxygen defects and the photoluminescence property of ZnO nanoparticles: A spectroscopic view

Prashant K. Sharma, Avinash C. Pandey, Grzegorz Zolnierkiewicz, Nikos Guskos, and Czeslaw Rudowicz
The present paper deals with the synthesis and characterization of ZnO nanoparticles obtained by coprecipitation method at three different pH conditions. Samples characterizations aimed at understanding their spectroscopic properties are carried out using a variety of experimental techniques. X-ray ... [J. Appl. Phys. 106, 094314 (2009)] published Fri Nov 13, 2009.

Frequency response of cantilever beams immersed in compressible fluids with applications to the atomic force microscope

Cornelis A. Van Eysden and John E. Sader
The dynamics of microcantilever beams can be strongly affected by immersion in fluid. While the importance of viscosity for devices of microscale dimensions is well established, the significance of fluid compressibility has not been investigated in detail. Here, we present a rigorous theoretical mod ... [J. Appl. Phys. 106, 094904 (2009)] published Fri Nov 13, 2009.

Quantum-coupled single-electron thermal to electric conversion scheme

D. M. Wu, P. L. Hagelstein, P. Chen, K. P. Sinha, and A. Meulenberg
Thermal to electric energy conversion with thermophotovoltaics relies on radiation emitted by a hot body, which limits the power per unit area to that of a blackbody. Microgap thermophotovoltaics take advantage of evanescent waves to obtain higher throughput, with the power per unit area limited by ... [J. Appl. Phys. 106, 094315 (2009)] published Fri Nov 13, 2009.

Study on the paramagnetic relaxation mechanisms by Rb nuclear magnetic resonance in RbMnCl crystals of ABX type

Ae Ran Lim
The spin-lattice relaxation time, T, for Rb nuclei in RbMnCl crystals was investigated, and a phase transition was found near 383 K (=T). The Rb spectrum changes near T from two central resonance lines due to Rb(1) and Rb(2) to one Rb central resonance line, and this change is due to changes in the ... [J. Appl. Phys. 106, 093522 (2009)] published Fri Nov 13, 2009.

A benchmark study on the thermal conductivity of nanofluids

Jacopo Buongiorno, David C. Venerus, Naveen Prabhat, Thomas McKrell, Jessica Townsend et al.
This article reports on the International Nanofluid Property Benchmark Exercise, or INPBE, in which the thermal conductivity of identical samples of colloidally stable dispersions of nanoparticles or nanofluids, was measured by over 30 organizations worldwide, using a variety of experimental approac ... [J. Appl. Phys. 106, 094312 (2009)] published Fri Nov 13, 2009.

Comment on Influence of atomic force microscope cantilever tilt and induced torque on force measurements [J. Appl. Phys. 103, 064513 (2008)]

Fei Wang
In a recent article, Edwards et al. [J. Appl. Phys. 103, 064513 (2008)] examined the effect of cantilever tilt and induced torque on the effective normal spring constant for both sharp tips and spherical probes, and in contrast to previous studies, they found that induced tip torque can act to eithe ... [J. Appl. Phys. 106, 096103 (2009)] published Fri Nov 13, 2009.

Upper critical field and Raman spectra of MgB thin films irradiated with low energy oxygen ion

J. Wang, C. G. Zhuang, J. Li, Y. Z. Wang, Q. R. Feng et al.
The structure, upper critical field, and Raman spectrum of epitaxial MgB thin films irradiated by 300 keV O ions have been investigated. Lattice parameter c expands after irradiation. There is a significant increase in upper critical field in the moderately irradiated films, while the critical tempe ... [J. Appl. Phys. 106, 093915 (2009)] published Fri Nov 13, 2009.

X-ray irradiation effects on the trapping properties of CdZnTe detectors

B. Fraboni, L. Pasquini, A. Castaldini, A. Cavallini, and P. Siffert
CdZnTe-based detectors possess unique properties as room-temperature x- and gamma-ray detectors. We report on the effects of x-ray irradiation on CdZnTe and CdTe:Cl detectors with increasing x-ray doses. We correlate the macroscopic performance of the detectors, investigated by gamma-ray spectroscop ... [J. Appl. Phys. 106, 093713 (2009)] published Fri Nov 13, 2009.

Influence of nanoparticle height on plasmonic resonance wavelength and electromagnetic field enhancement in two-dimensional arrays

John Henson, Jeff DiMaria, and Roberto Paiella
A detailed experimental and theoretical study of the plasmonic properties of silver nanoparticle arrays as a function of nanoparticle height is presented. Specifically, several square periodic arrays have been fabricated by electron beam lithography and characterized via transmission spectroscopy me ... [J. Appl. Phys. 106, 093111 (2009)] published Fri Nov 13, 2009.

Whispering-gallery-modelike resonance of luminescence from a single hexagonal ZnO microdisk

Sung Soo Kim, Yong-Jin Kim, Gyu-Chul Yi, and Hyeonsik Cheong
We have imaged the luminescence from a single ZnO hexagonal microdisk using a confocal-microscopy-based imaging spectroscopy system. Micro-Raman scattering measurements confirm that the ZnO microdisk was grown with the direction of the c-axis normal to its surface and the Si substrate. The photolumi ... [J. Appl. Phys. 106, 094310 (2009)] published Thu Nov 12, 2009.

Creep and its effect on Sn whisker growth

John W. Osenbach
A comprehensive quantitative whisker growth theory has been developed. In this theory whisker growth is controlled by the ratio of the long range grain boundary diffusion creep relaxation rate to the short range creep relaxation rate. The theory relies solely on solid state diffusion effects and doe ... [J. Appl. Phys. 106, 094903 (2009)] published Thu Nov 12, 2009.

Optical properties and switching behavior in GdO:Er nanophosphor

S. K. Singh, K. Kumar, and S. B. Rai
The upconversion (UC) efficient GdO:Er nanophosphor powder has been synthesized through the combustion route using urea as a reducing agent. The UC studies have been carried out using 532 nm excitation, and the samples show intense emission bands in ultraviolet (340 and 383 nm), blue (411, 458, 472, ... [J. Appl. Phys. 106, 093520 (2009)] published Thu Nov 12, 2009.

Magnetic-field transfer of water molecules

Toshiaki Osuga and Hozumi Tatsuoka
Thermal agitation induces the rotational motion of the two positively charged hydrogens around the oxygen nucleus in a water molecule, which forms an electric current with a short duration, generating a Lorentz force in a uniform static magnetic field. Since the center of gravity of a water molecule ... [J. Appl. Phys. 106, 094311 (2009)] published Thu Nov 12, 2009.

Reliability assessment and degradation analysis of 1.3 [mu]m GaInNAs lasers

W. Lu, S. Bull, J. J. Lim, R. MacKenzie, S. Sujecki et al.
The degradation of 1.3 [mu]m GaInNAs lasers was investigated using accelerated aging tests. This was followed by comprehensive characterization, including standard light-current-voltage (L-I-V) characterization, capacitance measurements, photoluminescence microscopy (PLM), on-axis amplified spontan ... [J. Appl. Phys. 106, 093110 (2009)] published Thu Nov 12, 2009.

Tunable lattice strain in vertically aligned nanocomposite (BiFeO):(SmO) thin films

Zhenxing Bi, Joon Hwan Lee, Hao Yang, Quanxi Jia, Judith L. MacManus-Driscoll et al.
Unique epitaxial two-phase vertically aligned nanocomposite (VAN) (BiFeO):(SmO) thin films were deposited on SrTiO(001) substrates by pulsed laser deposition. The VAN thin films exhibit a highly ordered vertical columnar structure with high epitaxial quality. We demonstrate that the strains of the t ... [J. Appl. Phys. 106, 094309 (2009)] published Wed Nov 11, 2009.

Formation of atomic gold chain on hydrogen terminated Si(001):3 x 1 surface: A density functional study

Shyamal Konar, Bikash C. Gupta, and Prasenjit Sen
Electronic structure calculations are carried out for investigating the formation of a stable atomic gold wire on the hydrogen terminated Si(001):3 x 1 [HSi(001):3 x 1] surface. The HSi(001):3 x 1 surface is patterned in various ways by removing desired hydrogen atoms from the surface. Gold atoms ar ... [J. Appl. Phys. 106, 093712 (2009)] published Wed Nov 11, 2009.

Experimental and finite-element method studies of the effects of ferromagnetic substrate on the total ac loss in a rolling-assisted biaxially textured substrate YBaCuO tape exposed to a parallel ac magnetic field

Doan N. Nguyen, Stephen P. Ashworth, and Jeffrey O. Willis
This paper presents a study of the total ac loss characteristics of a rolling-assisted biaxially textured substrate (RABiTS) YBaCuO (YBCO) sample exposed to a parallel ac magnetic field. The results have shown that, for a given applied magnetic field and transport current, a RABiTS YBCO tape can gen ... [J. Appl. Phys. 106, 093913 (2009)] published Wed Nov 11, 2009.

Self-assembled multilayers and enhanced superconductivity in (YBaCuO):(BaZrO) nanocomposite films

H. Yang, H. Wang, B. Maiorov, J. Lee, D. Talbayev et al.
Nanocomposite (YBaCuO):(BaZrO) thin films were fabricated on (001) oriented SrTiO substrates by pulsed laser deposition using a single uniformly mixed target. Both x-ray diffraction and transmission electron microscopy revealed remarkable, spontaneous formation of YBaCuO (YBCO) and BaZrO (BZO) multi ... [J. Appl. Phys. 106, 093914 (2009)] published Wed Nov 11, 2009.

Stress-induced phenomena in nanosized copper interconnect structures studied by x-ray and electron microscopy

Ehrenfried Zschech, Rene Huebner, Dmytro Chumakov, Oliver Aubel, Daniel Friedrich et al.
We present the first dynamic study of damage mechanisms in nanosized on-chip Cu interconnects caused by stress-induced voiding in advanced integrated circuits. Synchrotron-based transmission x-ray microscopy is applied to visualize the void evolution and conical dark-field analysis in the transmissi ... [J. Appl. Phys. 106, 093711 (2009)] published Wed Nov 11, 2009.

Magnetic properties and large magnetocaloric effect of DyPt

Parul Arora, M. K. Chattopadhyay, and S. B. Roy
We report the results of magnetization and heat capacity measurements on the rare-earth intermetallic compound DyPt as a function of temperature and magnetic field. These studies reveal the presence of short range magnetic correlations in DyPt above the Curie temperature, well inside the paramagneti ... [J. Appl. Phys. 106, 093912 (2009)] published Wed Nov 11, 2009.

Simultaneous measurement of temperature and thermal stress in AlGaN/GaN high electron mobility transistors using Raman scattering spectroscopy

T. Batten, J. W. Pomeroy, M. J. Uren, T. Martin, and M. Kuball
Raman spectroscopy, utilizing both the GaN E and A(LO) phonon modes, has been used to simultaneously probe temperature and thermal stress in operating AlGaN/GaN high electron mobility transistors (HEMTs). Temperature and thermal stress profiles across the active region of an AlGaN/GaN HEMT were dete ... [J. Appl. Phys. 106, 094509 (2009)] published Wed Nov 11, 2009.

Calculation of the magnetic energy barrier in nanostructured cells of synthetic ferrimagnets

C. W. Han, J. K. Han, and S. H. Lim
A method is proposed to calculate the magnetic energy barrier of nanostructured cells of synthetic ferrimagnets. An important feature of the method is the use of an equation for the total energy that contains the magnetostatic fields at the saddle point as parameters of the energy equation. With no ... [J. Appl. Phys. 106, 094508 (2009)] published Wed Nov 11, 2009.

Influence of combined external stress and electric field on electric properties of 0.5% Fe-doped lead zirconate titanate ceramics

J. Suchanicz, N.-T. H. Kim-Ngan, K. Konieczny, I. Jankowska-Sumara, D. Sitko et al.
Influence of uniaxial pressure (01000 bars) applied parallel to or perpendicularly to the ac or dc electric field (in one-dimensional or two-dimensional manner) on dielectric and ferroelectric properties of hard lead zirconate titanate (PZT) ceramics were investigated. The experimental results revea ... [J. Appl. Phys. 106, 094109 (2009)] published Wed Nov 11, 2009.

Single-crystal elastic properties of (Y,Yb)AlO

Hauke Marquardt, Sergio Speziale, Sandro Jahn, Steffen Ganschow, and Frank R. Schilling
Brillouin scattering experiments were performed on single crystals in the solid solution series YAlOYbAlO (with X=0,0.39,0.81,1). Elastic stiffness tensor, bulk modulus K, Young's modulus, and shear modulus were determined, which were previously only known for the yttrium end member. In our experime ... [J. Appl. Phys. 106, 093519 (2009)] published Wed Nov 11, 2009.

Effect of indium content on performance and reliability of InGaN/GaN light-emitting diodes

Z. L. Li, S. Tripathy, P. T. Lai, and H. W. Choi
While longer wavelength emission from InGaN/GaN light-emitting diodes (LEDs) can be achieved by increasing the indium (In) content in the quantum wells, the increased In content gives rise to side effects to the material and device performance and reliability. It was found that the induced strain in ... [J. Appl. Phys. 106, 094507 (2009)] published Tue Nov 10, 2009.

Structure of orthorhombic martensitic phase in binary TiNb alloys

S. Banumathy, R. K. Mandal, and A. K. Singh
The structure of orthorhombic (alpha) martensitic phase of Ti8Nb, Ti12Nb, and Ti16Nb alloys has been investigated using Rietveld refinement of x-ray diffraction data. The chemical analysis data have been used to determine the site occupancy of initial models. A limit of the Wyckoff positions has bee ... [J. Appl. Phys. 106, 093518 (2009)] published Tue Nov 10, 2009.

Tb luminescence by energy transfer from Eu in (Sr,Ba)SiO phosphor

Ryosuke Hiramatsu, Kunio Ishida, Fumihiko Aiga, Yumi Fukuda, Naotoshi Matsuda et al.
(Sr,Ba)SiO phosphors co-doped with Tb and Eu were prepared by a conventional solid-state reaction method. Prepared (Sr,Ba)SiO:Tb,Eu phosphors had characteristic luminescent spectra excited under near-UV excitation in which both the broadband spectrum assigned to Eu and the narrowband spectrum assign ... [J. Appl. Phys. 106, 093513 (2009)] published Tue Nov 10, 2009.

Hydrogen induced lattice expansion and crystallinity degradation in palladium nanoparticles: Effect of hydrogen concentration, pressure, and temperature

Manika Khanuja, B. R. Mehta, Pragya Agar, P. K. Kulriya, and D. K. Avasthi
A detailed structural study involving in situ glancing angle x-ray diffraction (GAXRD) analysis carried out on Pd nanoparticle and thin film samples at hydrogen concentrations of 2%, 5%, and 10% over temperature ranging from 100 to 55 degrees C and hydrogen pressures ranging from 250 to 1000 mbars ... [J. Appl. Phys. 106, 093515 (2009)] published Tue Nov 10, 2009.

Analysis of inhomogeneous Ge/SiC heterojunction diodes

P. M. Gammon, A. Perez-Tomas, V. A. Shah, G. J. Roberts, M. R. Jennings et al.
In this article Schottky barrier diodes comprising of a n-n germanium-silicon carbide (GeSiC) heterojunction are electrically characterized. Circular transmission line measurements prove that the nickel front and back contacts are Ohmic, isolating the Ge/SiC heterojunction as the only contributor to ... [J. Appl. Phys. 106, 093708 (2009)] published Tue Nov 10, 2009.

Ultrasonic harmonic generation from fatigue-induced dislocation substructures in planar slip metals and assessment of remaining fatigue life

John H. Cantrell
An analytical model is presented of the microelastic-plastic nonlinearities resulting from the interactions of a stress perturbation with dislocation substructures and cracks that evolve during cyclic fatigue of planar slip metals. The interactions are quantified by a material nonlinearity parameter ... [J. Appl. Phys. 106, 093516 (2009)] published Tue Nov 10, 2009.

Theoretical analysis of thermally tunable microring resonator filters made of dielectric-loaded plasmonic waveguides

Odysseas Tsilipakos, Traianos V. Yioultsis, and Emmanouil E. Kriezis
Microring resonator filters, which are made of dielectric-loaded surface plasmon polariton waveguides and operate in the telecom spectral range, are thoroughly analyzed by means of vectorial three dimensional (3D) finite element method (FEM) simulations. The filters' functional characteristics, such ... [J. Appl. Phys. 106, 093109 (2009)] published Tue Nov 10, 2009.

Effects of pressure on charge transport and magnetic properties of LaSrMnO layered manganite

M. Kumaresavanji, M. S. Reis, Y. T. Xing, and M. B. Fontes
We have studied the effects of hydrostatic pressure on the electrical transport and magnetic properties of LaSrMnO layered manganite up to 25 kbars. At ambient pressure, the compound exhibits a ferromagnetic transition accompanied by a metal-insulator transition (T) at 118 K. Increasing pressure ind ... [J. Appl. Phys. 106, 093709 (2009)] published Tue Nov 10, 2009.

Roles of microcracking and phase transition on electric fatigue for [001]-oriented Pb(MgNb)OPbTiO single crystals

F. Fang, W. Yang, and X. Luo
Microstructure and polarization degradation are observed under cyclic electric loadings for [001]-oriented Pb(MgNb)OPbTiO single crystals. Microcracking and phase transition are found to bear effect for polarization degradation. Upon cyclic electric loading with a comparatively low field magnitude, ... [J. Appl. Phys. 106, 094107 (2009)] published Tue Nov 10, 2009.

Theoretical investigation of half metallicity in Fe/Co/Ni doped ZnSe material systems

B. Amin and Iftikhar Ahmad
In the present investigation, we evaluated the half-metallic-ferromagnetic/antiferromagnetic nature of Fe/Co/Ni doped ZnSe material systems. Our calculations show that for the majority spin channel, ZnFeSe, ZnCoSe, and ZnNiSe, are semiconductors, and for the minority spin channel, they are conductor ... [J. Appl. Phys. 106, 093710 (2009)] published Tue Nov 10, 2009.

A first principles study on optical transparency mechanism in Dy doped alpha-SiAlON ceramics

H. M. Zhong, Q. Liu, J. Jiang, G. Y. Sun, and Y. Luo
Dy doped alpha-SiAlON ceramics prepared by the hot-pressing method show a high optical transmittance value, >70%, in the infrared region of 1.54.5 [mu]m. First principles calculations have been carried out to reveal the underlying transparency mechanism. It is found that the valence shell of doped ... [J. Appl. Phys. 106, 093514 (2009)] published Tue Nov 10, 2009.

Recombination lifetimes in highly aluminum-doped silicon

Jan Schmidt, Nils Thiemann, Robert Bock, and Rolf Brendel
We show that the recombination lifetimes measured in highly aluminum-doped p-type silicon (Al-p) regions, fabricated by means of screen printing and firing of aluminum paste, are three orders of magnitude larger than the lifetimes expected from the extrapolation of the lifetime data measured on alum ... [J. Appl. Phys. 106, 093707 (2009)] published Tue Nov 10, 2009.

Effects of Mn doping on dielectric and ferroelectric properties of (Pb,Sr)TiO films on (111) Pt/Ti/SiO/Si substrates

J. Yang, X. J. Meng, M. R. Shen, J. L. Sun, and J. H. Chu
A series of Mn doped PbSrTiO (PSMT) films with dopant concentrations from 0 to 10 mol % was fabricated on (111) Pt/Ti/SiO/Si substrates by chemical solution deposition. Their microstructure, ferroelectric, and dielectric properties were investigated, and Mn doping was found to have a significant in ... [J. Appl. Phys. 106, 094108 (2009)] published Tue Nov 10, 2009.

Resistive switching in aluminum/anodized aluminum film structure without forming process

W. Zhu, T. P. Chen, Z. Liu, M. Yang, Y. Liu et al.
Metal-insulator-metal (MIM) structure was fabricated by partially anodizing aluminum film followed by deposition of another aluminum film. Unipolar resistive switching between a high-resistance state and a low-resistance state with a high resistance ratio (>~10) was observed from the structure. The ... [J. Appl. Phys. 106, 093706 (2009)] published Tue Nov 10, 2009.

Nonlinear refraction properties of nickel oxide thin films at 800 nm

Ronaldo P. de Melo, Jr., Blenio J. P. da Silva, Francisco Eroni P. dos Santos, A. Azevedo, and Cid B. de Araujo
Measurements of the nonlinear refractive index, n, of nickel oxide films prepared by controlled oxidation of nickel films deposited on substrates of soda-lime glass are reported. The structure and morphology of the samples were characterized by scanning electron microscopy, atomic force microscopy, ... [J. Appl. Phys. 106, 093517 (2009)] published Tue Nov 10, 2009.

Self-sustained etch masking: A general concept to initiate the formation of nanopatterns during ion erosion

S. Le Roy, E. Barthel, N. Brun, A. Lelarge, and E. Sondergard
A material allowing for rapid and reliable formation of nanopatterned surfaces is an important issue in many areas of science today. Self-organized pattern formation induced by ion erosion is a promising bottom-up approach. In the case of the III-V semiconductors, this method can lead to several rem ... [J. Appl. Phys. 106, 094308 (2009)] published Tue Nov 10, 2009.

Multiple enhanced transmission bands through compound periodic array of rectangular holes

Jian-Qiang Liu, Xing-Bing Chao, Jian-Ning Wei, Meng-Dong He, Ling-Ling Wang et al.
Based on the finite-difference time-domain method, we demonstrate multiple enhanced transmission bands through subwavelength compound periodic array of rectangular holes by adjusting the cutoff wavelength of each hole. The results show that the transmission spectrum of this structure is almost a com ... [J. Appl. Phys. 106, 093108 (2009)] published Tue Nov 10, 2009.

Impact of postgrowth annealing on spin-glass ordering and exchange bias in SrMnO nanoribbons

J. Y. Yu, S. L. Tang, L. Zhai, Y. Deng, Y. G. Shi et al.
The magnetic properties of as-grown single-crystal SrMnO nanoribbons synthesized by a simple molten-salt method can be significantly improved by a heat-treatment procedure, which enhances the ferromagnetism and spin-glass behavior. These enhanced properties might originate from a spin structure modu ... [J. Appl. Phys. 106, 093909 (2009)] published Mon Nov 9, 2009.

Adjusting the resonant frequency and loss of dendritic left-handed metamaterials with fractal dimension

Weiren Zhu and Xiaopeng Zhao
Left-handed metamaterials (LHMs) with fractal dendritic cells have recently been demonstrated at both microwave and infrared frequencies. Here, we try to utilize only a single parameter, the fractal dimension, to manipulate the geometries of dendritic structures, and then adjust the resonant behavio ... [J. Appl. Phys. 106, 093511 (2009)] published Mon Nov 9, 2009.

One-dimensional quantum waveguide theory of Rashba electrons

Duan-Yang Liu, Jian-Bai Xia, and Yia-Chung Chang
The ballistic spin transport in one-dimensional waveguides with the Rashba effect is studied. Due to the Rashba effect, there are two electron states with different wave vectors for the same energy. The wave functions of two Rashba electron states are derived, and it is found that their phase depend ... [J. Appl. Phys. 106, 093705 (2009)] published Mon Nov 9, 2009.

Temperature-dependent electrical behavior of LaSrMnO-buffered BiLaFeO thin films

Y. Wang and J. Wang
Temperature-dependent ferroelectric and dielectric behaviors of LaSrMnO-buffered BiLaFeO thin films were investigated. It was observed that the coercive voltage remarkably increases with decreasing temperature, and for a fixed driving voltage the area of hysteresis loop demonstrates a maximum at a c ... [J. Appl. Phys. 106, 094106 (2009)] published Mon Nov 9, 2009.

Magnetic properties of FeCu alloys prepared by pulsed electrodeposition

R. D. Noce, O. D. M. Gomes, S. D. de Magalhaes, W. Wolf, R. B. Guimaraes et al.
FeCu metastable alloys were prepared by pulsed electrodeposition for 550) are reminiscent of those observed in FeCu a ... [J. Appl. Phys. 106, 093907 (2009)] published Mon Nov 9, 2009.

Low energy photoelectron diffraction analysis at high angular resolution of Cu and Mn/Cu surfaces

G. P. Cousland, A. E. Smith, J. D. Riley, and A. P. J. Stampfl
X-ray photoelectron diffraction simulations using a real-space approach are shown to accurately produce the extraordinarily detailed photoelectron diffraction pattern from Cu{111} at an electron kinetic energy of 523.5 eV. These same simulations show that most sensitivity is obtained when using low ... [J. Appl. Phys. 106, 093510 (2009)] published Mon Nov 9, 2009.

Acoustoelectric effects in very high-mobility p-SiGe/Ge/SiGe heterostructure

I. L. Drichko, A. M. Diakonov, E. V. Lebedeva, I. Yu. Smirnov, O. A. Mironov et al.
Measurement results of the acoustoelectric effects [surface acoustic waves (SAW) attenuation and velocity] in a high-mobility p-SiGe/Ge/SiGe structure are presented. The structure was low-energy plasma-enhanced chemical vapor deposition grown with a two-dimensional (2D) channel buried in the straine ... [J. Appl. Phys. 106, 094305 (2009)] published Mon Nov 9, 2009.

Free flexural vibration studies of double-walled carbon nanotubes with different boundary conditions and modeled as nonlocal Euler beams via the Galerkin method

A. Shakouri, R. M. Lin, and T. Y. Ng
In this work, a numerical Galerkin approach which can handle different boundary conditions in a general manner is presented to study the free vibration of double-walled carbon nanotubes (DWCNTs) modeled as nonlocal Euler beams. The effects of small scale, different boundary conditions, and geometric ... [J. Appl. Phys. 106, 094307 (2009)] published Mon Nov 9, 2009.

Size quantization effect in highly stable UV emitting HgTe nanoparticles: Structure and optical properties

A. M. P. Hussain, S. N. Sarangi, and S. N. Sahu
We report a simple one pot aqueous chemical synthesis route to fabricate very small and highly stable HgTe nanoparticles (NPs) capped with L-cysteine ethyl ester hydrochloride (LEEH). The LEEH concentration has found to be critical for desired size NP synthesis. Structural analyses by grazing angle ... [J. Appl. Phys. 106, 094306 (2009)] published Mon Nov 9, 2009.

Growth kinetics of Ge crystals on silicon oxide by nanoscale silicon seed induced lateral epitaxy

V. D. Cammilleri, V. Yam, F. Fossard, C. Renard, D. Bouchier et al.
In this paper, we present our studies on the growth kinetics of Ge crystals on silicon oxide by nanoscale seed induced lateral epitaxy. We propose a simple and reliable method based on standard local oxidation of silicon technique for creating nanoscale silicon seeds at the edge of thermally grown s ... [J. Appl. Phys. 106, 093512 (2009)] published Mon Nov 9, 2009.

N codoping induced ferromagnetism in ZnO:Co (10[overline 1]0) thin films

M. H. N. Assadi, Y. B. Zhang, and S. Li
By first-principles density functional calculations with generalized gradient approximation ZnO:Co (10[overline 1]0) thin films have been demonstrated not to exhibit a ferromagnetic behavior in the absence of any additional carrier doping. Virtual crystal approximation is employed to introduce contr ... [J. Appl. Phys. 106, 093911 (2009)] published Mon Nov 9, 2009.

Drift-diffusion modeling of photocurrent transients in bulk heterojunction solar cells

Inchan Hwang, Christopher R. McNeill, and Neil C. Greenham
We utilize a time-dependent drift-diffusion model incorporating electron trapping and field-dependent charge separation to explore the device physics of organic bulk-heterojunction solar cells based on blends of poly(3-hexylthiophene) (P3HT) with a red polyfluorene copolymer. The model is used to re ... [J. Appl. Phys. 106, 094506 (2009)] published Mon Nov 9, 2009.

The cooling field and the exchange bias in ferromagnet/antiferromagnet bilayers

X. Y. Xu, H. Y. Tian, X. Qian, and J. G. Hu
The effect of the cooling field (h) on the exchange bias (h) has been investigated in ferromagnet/antiferromagnet (FM/AFM) bilayers with the different types of interface exchange coupling. The results show that for the antiferromagnetic interface coupling, h can change from negative values to positi ... [J. Appl. Phys. 106, 093910 (2009)] published Mon Nov 9, 2009.

Magnetic frustration effect in Mn-rich SrMnFeMoO system

Asok Poddar and Chandan Mazumdar
Variation in lattice parameters and magnetic properties of SrMnFeMoO (0<=x<=0.4) has been studied in the present work. Our findings suggest that the crystal structures at room temperature for all the compositions studied here are pseudocubic in nature. Substitution of as small as 10% Fe in place of ... [J. Appl. Phys. 106, 093908 (2009)] published Mon Nov 9, 2009.

A criterion for evaluating glass-forming ability of alloys

Guo-Hua Zhang and Kuo-Chih Chou
A criterion defined as theta=(T+T)/T[(TT)/T] (where T is the onset crystallization temperature, T is the glass transition temperature, T is liquidus temperature, and alpha is an exponent) is proposed to evaluate the glass-forming ability of alloy systems. Regression analysis between the logarithm of ... [J. Appl. Phys. 106, 094902 (2009)] published Mon Nov 9, 2009.

Polarimetry and Schlieren diagnostics of underwater exploding wires

A. V. Fedotov-Gefen and Ya. E. Krasik
Nondisturbing laser-probing polarimetry (based on the Faraday and Kerr effects) and Schlieren diagnostics were used in the investigation of underwater electrical wire explosion. Measuring the polarization plane rotation angle of a probing laser beam due to the Faraday effect allows one to determine ... [J. Appl. Phys. 106, 093303 (2009)] published Mon Nov 9, 2009.