Journal of Applied Physics: All Topics

Super critical thickness SiGe-channel heterostructure p-type metal-oxide-semiconductor field-effect transistors using laser spike annealing

Cait Ni Chleirigh, XiaoRu Wang, Gana Rimple, Yun Wang, N. David Theodore et al.
Strained Si/strained SiGe/relaxed SiGe heterostructure p-type metal-oxide-semiconductor field-effect transistors (MOSFETs) with high mobility and low leakage are demonstrated using laser spike annealing, despite a strained SiGe channel thickness that is two times the equilibrium critical thickness. ... [J. Appl. Phys. 103, 104501 (2008)] published Fri May 16, 2008.

Dielectric functions and optical constants modeling for CuIn[sub 3]Se[sub 5] and CuIn[sub 5]Se[sub 8]

M. Leon, R. Serna, S. Levcenko, A. Nicorici, J. M. Merino et al.
The complex dielectric functions, epsilon(omega)=epsilon(omega)+iepsilon(omega), of CuInSe and CuInSe crystals with different Cu contents have been determined in the 0.84.7 eV photon energy range by using spectroscopic ellipsometry. The spectral dependence of the real, epsilon(omega), and imaginary, ... [J. Appl. Phys. 103, 103503 (2008)] published Fri May 16, 2008.

Nonequilibrium population distribution in excited electronic states of Tb[sup 3+] in Y[sub 3]Al[sub 5]O[sub 12]

John B. Gruber, Dhiraj K. Sardar, Kelly L. Nash, Uygun V. Valiev, Vladimir Yu. Sokolov et al.
The Zeeman effect has been studied within the green range of luminescence due to the radiative 4f-->4f transitions D-->F for the rare earth ion Tb in yttrium aluminum garnet (YAlO) at a sample temperature of 85 K. The special features associated with the magnetic field dependence of the Zeeman split ... [J. Appl. Phys. 103, 103103 (2008)] published Fri May 16, 2008.

Conversion efficiencies of electron beam energy to vacuum ultraviolet light for Ne, Ar, Kr, and Xe excited with continuous electron beams

A. Morozov, T. Heindl, R. Krucken, A. Ulrich, and J. Wieser
Continuous 815 keV electron beams were used to excite Ne, Ar, Kr, and Xe at pressures ranging from 75 to 1400 hPa. Conversion efficiencies of the energy deposited by the electron beam in the gas to vacuum ultraviolet light emitted from excimers are obtained. At pressures above 500 hPa, the effi ... [J. Appl. Phys. 103, 103301 (2008)] published Fri May 16, 2008.

The persistent photoconductivity effect in AlGaN/GaN heterostructures grown on sapphire and SiC substrates

Engin Arslan, Serkan Butun, S. Bora Lisesivdin, Mehmet Kasap, Suleyman Ozcelik et al.
In the present study, we reported the results of the investigation of electrical and optical measurements in AlGaN/GaN heterostructures (x=0.20) that were grown by way of metal-organic chemical vapor deposition on sapphire and SiC substrates with the same buffer structures and similar conditions. We ... [J. Appl. Phys. 103, 103701 (2008)] published Fri May 16, 2008.

Transversely isotropic elastic properties of single-walled carbon nanotubes by a rectangular beam model for the C[Single Bond]C bonds

Haijun Li and Wanlin Guo
Continuum mechanics modeling of carbon nanotubes has long been an attractive issue, but how to reflect exactly the physics essential of the atomic bonds still remains to be a challenging problem. To capture the distinguishing in-plane sigma-sigma and out-of-plane sigma-pi bond angle bending rigiditi ... [J. Appl. Phys. 103, 103501 (2008)] published Fri May 16, 2008.

Low saturation fluence in a semiconductor saturable electroabsorber mirror operated in a self-biased regime

B. S. Ryvkin, K. Panajotov, and E. A. Avrutin
A semiconductor saturable absorber mirror utilizing the electroabsorption effect on a self-biased stack of extremely shallow quantum wells is proposed and analyzed theoretically and numerically. The saturation flux and recovery time of the proposed device when operated with picosecond incident pulse ... [J. Appl. Phys. 103, 103102 (2008)] published Fri May 16, 2008.

Vibronic nature of hafnium oxide/silicon interface states investigated by capacitance frequency spectroscopy

O. Engstrom, B. Raeissi, and J. Piscator
Using a method based on the frequency dependence of capacitance, cross sections for electron capture into energy states at the interlayer/silicon interface have been investigated for HfO that is deposited on silicon by reactive sputtering. We find that the capture cross sections are thermally activa ... [J. Appl. Phys. 103, 104101 (2008)] published Fri May 16, 2008.

Valence band offset at interfaces between CuI and indium sulfides

Igor Konovalov and Liudmila Makhova
The energy differences between In 3d, In 4d, and S 2p core levels are almost the same in beta-InS, CuInS, AgInS, CuInS, InS, and InS semiconductors. The system of these core levels provides a reference energy that can be used to put the valence band edges of these materials on a common energy scale. ... [J. Appl. Phys. 103, 103702 (2008)] published Fri May 16, 2008.

Identification and quantification of components in ternary vapor mixtures using a microelectromechanical-system-based electronic nose

Weichang Zhao, Lal A. Pinnaduwage, John W. Leis, Anthony C. Gehl, Steve L. Allman et al.
We report the experimental details on the successful application of the electronic nose approach to identify and quantify components in ternary vapor mixtures. Preliminary results have recently been presented [L. A. Pinnaduwage et al., Appl. Phys. Lett. 91, 044105 (2007)]. Our microelectromechanical ... [J. Appl. Phys. 103, 104902 (2008)] published Fri May 16, 2008.

Photoelectron spectroscopic investigation of nitrogen chemical states in ZnO: (N,Ga) thin films

H. Wang, H. P. Ho, and J. B. Xu
Fabrication of high quality p-type ZnO is the main challenge in recent ZnO research that prevents the practical application of ZnO-based devices in optoelectronics. The mechanism behind is thought to be due to self-compensation of native defects and/or dopant-induced donors. In this report, we inves ... [J. Appl. Phys. 103, 103704 (2008)] published Fri May 16, 2008.

Defects and transport in complex oxide thin films

Tsuyoshi Ohnishi, Keisuke Shibuya, Takahisa Yamamoto, and Mikk Lippmaa
Epitaxial oxide thin films are at the heart of new oxide electronic applications, such as excitonic ultraviolet light-emitting diodes and resistive switching memories. Complex oxide films are often grown by pulsed laser deposition (PLD) because the technique is believed to be material agnostic. Here ... [J. Appl. Phys. 103, 103703 (2008)] published Fri May 16, 2008.

Investigation of neodymium-diffused yttrium vanadate waveguides by confocal microluminescence

A. Benayas, D. Jaque, S. J. Hettrick, J. S. Wilkinson, and D. P. Shepherd
We report on the confocal microspectroscopic characterization of planar optical waveguides fabricated in yttrium vanadate (YVO) crystals by thermal diffusion of neodymium ions. We have found that the waveguide formation is accompanied by Nd fluorescence quenching and by a redshift of the Nd sub-Star ... [J. Appl. Phys. 103, 103104 (2008)] published Fri May 16, 2008.

Analyses of the work required to delaminate a coating film from a substrate under oscillating load conditions and the film-substrate contact behavior after delamination

Jeng Luen Liou, Pal Jen Wei, Wen Long Liang, Chi Fong Ai, and Jen Fin Lin
Nanoindentation tests in which oscillating loads were applied to specimens were carried out to study the work (W) required for a coating film to delaminate from its substrate. A sharp increase in the indentation depth occurred during coating film delamination. A theoretical model was developed for t ... [J. Appl. Phys. 103, 103505 (2008)] published Fri May 16, 2008.

Heteroepitaxial growth of GaAs on (100) Ge/Si using migration enhanced epitaxy

H. Tanoto, S. F. Yoon, W. K. Loke, K. P. Chen, E. A. Fitzgerald et al.
In this paper, heteroepitaxial growth of GaAs on nominal (100) Ge/Si substrate was investigated. The root-mean square surface roughness of the sample where the first few monolayers of the GaAs were nucleated by migration enhanced epitaxy (MEE) is four times smaller compared to the sample without suc ... [J. Appl. Phys. 103, 104901 (2008)] published Fri May 16, 2008.

Manipulation of quantum interference effects in La[sub 0.39]Pr[sub 0.28]Ca[sub 0.33]MnO[sub 3 - delta] by p-n junction at high temperature

C. Wang, Y. Yang, Z. F. Li, X. S. Chen, S. C. Shen et al.
Manipulation of the magnetoresistance mechanism-quantum interference effects (QIEs) is achieved by controlling the hole density in a LaPrCaMnO depletion layer with the application of different biases to the LaPrCaMnO/SrNbTiO p-n junction. The positive magnetoresistance (PMR) induced by QIEs has bee ... [J. Appl. Phys. 103, 103705 (2008)] published Fri May 16, 2008.

Stress wave attenuation in ceramic plates

N. K. Naik, Rahul Goel, and Mandar D. Kulkarni
Studies on planar longitudinal stress wave attenuation in thin ceramic plates are presented using a wave tracking algorithm. The results are also experimentally validated. Ceramic plates consist of grains and grain boundaries. Elastic modulus and density of the grain boundaries are less than those o ... [J. Appl. Phys. 103, 103504 (2008)] published Fri May 16, 2008.

Band gap narrowing and radiative efficiency of silicon doped GaN

H. P. D. Schenk, S. I. Borenstain, A. Berezin, A. Schon, E. Cheifetz et al.
Radiative efficiency, band gap narrowing, and band filling are studied in Si-doped GaN films as a function of carrier concentration (n), using room and low temperature cathodoluminescence (CL). Using the Kane model, a band gap narrowing DeltaE of (3.60.6) x 10 and (2.60.6) x 10 n eV n is obtained ... [J. Appl. Phys. 103, 103502 (2008)] published Fri May 16, 2008.

Dependence of magnetic properties on micro- to nanostructure of CoNiFe films

Fernando M. F. Rhen and Saibal Roy
The magnetic properties of electrodeposited CoNiFe films with thicknesses varying from 0.20 to 10 [mu]m were studied. The films show a single face-centered-cubic CoNiFe phase with grain sizes ranging from 23 to 29 nm. The coercivity is controlled by a combination of the morphology and nanocrystalli ... [J. Appl. Phys. 103, 103901 (2008)] published Fri May 16, 2008.

Measurement of optical loss variation on thickness of InGaN optical confinement layers of blue-violet-emitting laser diodes

J. K. Son, S. N. Lee, H. S. Paek, T. Sakong, H. K. Kim et al.
An optical loss of GaN-based blue-violet laser diodes (BV-LDs) was measured by taking the intensity decay of edge emitting luminescence with respect to the distance from cleaved edge of a wafer to the position where an excitation laser was focused. Amplified spontaneous emission (ASE) was also inves ... [J. Appl. Phys. 103, 103101 (2008)] published Fri May 16, 2008.

Freestanding diffractive optical elements as light extractors for burning plasma experiments

D. Stutman, G. Caravelli, M. Finkenthal, G. Wright, D. Whyte et al.
Optical diagnostics will be critical for the operation and performance assessment of burning plasma experiments, such as ITER. At the same time, extracting light for these diagnostics with reflective mirrors becomes difficult in the burning plasma environment due to the deleterious effects of the pr ... [J. Appl. Phys. 103, 093307 (2008)] published Thu May 15, 2008.

Terahertz characterization of multi-walled carbon nanotube films

Ziran Wu, Lu Wang, Yitian Peng, Abram Young, Supapan Seraphin et al.
Multi-walled carbon nanotube films are characterized using terahertz time-domain spectroscopy. Both transmission and reflection experiments are performed in order to measure both the complex refractive index and the wave impedance. This method allows simultaneous extraction of both the permittivity ... [J. Appl. Phys. 103, 094324 (2008)] published Thu May 15, 2008.

Antireflection coating for improved optical trapping

Ying Hu, Timo A. Nieminen, Norman R. Heckenberg, and Halina Rubinsztein-Dunlop
An antireflection coating improves the trapping of high-index particles in optical tweezers by reducing the scattering force. This can allow the strong trapping of high-index particles that cannot normally be trapped, and the use of lower numerical aperture objectives while still obtaining strong tr ... [J. Appl. Phys. 103, 093119 (2008)] published Thu May 15, 2008.

Interfacial reactions between indium tin oxide and triphenylamine tetramer layers induced by photoirradiation

Toshikazu Satoh, Hisayoshi Fujikawa, Ichiro Yamamoto, Takanori Murasaki, and Yoshifumi Kato
The effects of photoirradiation on the interfacial chemical reactions between indium tin oxide (ITO) films and layers of triphenylamine tetramer (TPTE) were investigated by using in situ x-ray photoelectron spectroscopy (XPS). Thin TPTE layers deposited onto sputter-deposited ITO films were irradiat ... [J. Appl. Phys. 103, 093543 (2008)] published Thu May 15, 2008.

Bundling dynamics of single walled carbon nanotubes in aqueous suspensions

Goki Eda, Giovanni Fanchini, Alokik Kanwal, and Manish Chhowalla
A simple optical method based on absorption of monochromatic light to investigate the dynamics of single walled carbon nanotube (SWCNT) suspensions is described. The well dispersed suspensions display a complex behavior, exhibiting peaks due to resonant scattering from SWCNT bundles with increasing ... [J. Appl. Phys. 103, 093118 (2008)] published Thu May 15, 2008.

Numerical simulation of carrier collection and recombination at grain boundaries in Cu(In,Ga)Se[sub 2] solar cells

K. Taretto and U. Rau
Two-dimensional numerical device simulations investigate the influence of grain boundaries (GBs) on the performance of Cu(In,Ga)Se solar cells. We find that the electronic activity of grain boundaries can reduce the efficiency of Cu(In,Ga)Se solar cells from 20% to below 12% making proper passivatio ... [J. Appl. Phys. 103, 094523 (2008)] published Wed May 14, 2008.

To the kinetics of photoinduced volume changes in chalcogenide glasses

Rozalia Lukacs, Sergej D. Baranovskii, Peter Thomas, and Florian Gebhard
Recent experimental data on the dynamics of photoinduced volume changes in chalcogenide glasses are analyzed within a simple phenomenological model. Both kinetics of the volume expansion under continuous irradiation and that of the relaxation after the illumination is switched off are considered. Co ... [J. Appl. Phys. 103, 093541 (2008)] published Wed May 14, 2008.

A structural, magnetic, and M[o-umlaut]ssbauer spectral study of the DyCo[sub 4 - x]Fe[sub x]B compounds, with x = 0--3

Herve Mayot, Olivier Isnard, Fernande Grandjean, and Gary J. Long
The DyCoFeB compounds, with x=0, 1, 1.5, 2, 2.5, and 3, have been investigated by x-ray diffraction, magnetic measurements, and iron-57 Mossbauer spectroscopy. The substitution of cobalt by iron induces both an anisotropic increase in the unit-cell volume and a large increase in the Curie temperatur ... [J. Appl. Phys. 103, 093917 (2008)] published Wed May 14, 2008.

Electrostatic resonances of a negative-permittivity hemisphere

Henrik Kettunen, Henrik Wallen, and Ari Sihvola
This article studies the electric response of an electrically small hemispherical object with negative permittivity by computing its polarizability which is determined by two orthogonal components, the axial one and the transverse one. A certain range of negative permittivity values is found where t ... [J. Appl. Phys. 103, 094112 (2008)] published Wed May 14, 2008.

Femtosecond laser and swift-ion damage in lithium niobate: A comparative analysis

A. Garcia-Navarro, F. Agullo-Lopez, J. Olivares, J. Lamela, and F. Jaque
Relevant damage features associated with femtosecond pulse laser and swift-ion irradiations on LiNbO crystals are comparatively discussed. Experiments described in this paper include irradiations with repetitive femtosecond-laser pulses (800 nm, 130 fs) and irradiation with O, F, Si, and Cl ions at ... [J. Appl. Phys. 103, 093540 (2008)] published Wed May 14, 2008.

High-pressure Raman scattering study on zircon- to scheelite-type structural phase transitions of RCrO[sub 4]

Y. W. Long, L. X. Yang, Y. Yu, F. Y. Li, Y. X. Lu et al.
High-pressure Raman scattering experiments were performed on the zircon-type RCrO (R=Nd, Dy) compounds with the space group I4/amd by using diamond anvil cell techniques at room temperature. These two compounds exhibit similar Raman behaviors. Pressure-induced structural phase transitions were obser ... [J. Appl. Phys. 103, 093542 (2008)] published Wed May 14, 2008.

Increased conductivity of a hole transport layer due to oxidation by a molecular nanomagnet

S. Cheylan, J. Puigdollers, H. J. Bolink, E. Coronado, C. Voz et al.
Thin film transistors based on polyarylamine poly(N,N-diphenyl-N,Nbis(4-hexylphenyl)-[1,1biphenyl]-4,4-diamine (pTPD) were fabricated using spin coating in order to measure the mobility of pTPD upon oxidation. Partially oxidized pTPD with a molecular magnetic cluster showed an increase in mobility o ... [J. Appl. Phys. 103, 096110 (2008)] published Wed May 14, 2008.

Deformation potentials of the direct band gap of n-Al[sub 0.25]Ga[sub 0.75]As from controlled microscopic stress fields

Alessandro Alan Porporati, Naohide Furukawa, Wenliang Zhu, and Giuseppe Pezzotti
The deformation potentials have been experimentally determined for the direct gap of n-AlGaAs and compared to experimental and theoretical literature values. Highly localized spectroscopic stress assessments could be achieved using a field-emission electron gun as the energy source for stimulating c ... [J. Appl. Phys. 103, 096109 (2008)] published Wed May 14, 2008.

Electro-optical effect in films of azobenzene polycomplexes with cobalt

N. A. Davidenko, I. I. Davidenko, I. A. Savchenko, A. N. Popenaka, and L. B. Baath
Polymeric films containing azobenzene fragments with donor and acceptor groups were produced as well as films of polycomplexes of these fragments with cobalt. Absorption spectra of these films before and during application of an external electric field were investigated. Electro-optical properties o ... [J. Appl. Phys. 103, 094323 (2008)] published Wed May 14, 2008.

Magnetization process of lotus-type porous metals

H. Onishi, S. K. Hyun, H. Nakajima, S. Mitani, K. Takanashi et al.
Effects of porosity and pore orientation on the magnetization process were studied for lotus-type porous nickel and cobalt. It was confirmed that the saturation magnetization of porous metals varied linearly with the porosity, independent of the pore growth directions. Anisotropic behavior was clear ... [J. Appl. Phys. 103, 093539 (2008)] published Wed May 14, 2008.

An investigation of phonon decay in B[sub 12]As[sub 2] by Raman scattering spectroscopy

J. C. Gray, J. W. Pomeroy, M. Kuball, Z. Xu, J. H. Edgar et al.
Raman scattering spectroscopy was used to study the spectral linewidth and frequency of characteristic phonon modes of boron arsenide (BAs) as a function of temperature between 7 and 680 K. A combination of two- and three-phonon decay processes was found to dominate the dynamics of the intra-icosahe ... [J. Appl. Phys. 103, 093537 (2008)] published Tue May 13, 2008.

Controlled synthesis and characterization of Ag[sub 2]S films with varied microstructures and its role as asymmetric barrier layer in trilayer junctions with dissimilar electrodes

I. C. Lekshmi, G. Berera, Y. Afsar, G. X. Miao, T. Nagahama et al.
In this study, we examine the possibility of electrode-barrier interactions in modifying the electrical characteristics and current switching behavior of a trilayer junction with silver sulfide as the barrier layer. A series of AlAgSAg crossbar junction is fabricated by thermal evaporation technique ... [J. Appl. Phys. 103, 093719 (2008)] published Tue May 13, 2008.

Si interstitial contribution of F[sup +] implants in crystalline Si

Pedro Lopez, Lourdes Pelaz, R. Duffy, P. Meunier-Beillard, F. Roozeboom et al.
The F effect in crystalline Si is quantified by monitoring defects and B diffusion in samples implanted with 25 keV F and/or 40 keV Si. We estimate that about +0.4 Si interstitials are generated per implanted F ion, in agreement with the value resulting from the net separation of Frenkel pairs. For ... [J. Appl. Phys. 103, 093538 (2008)] published Tue May 13, 2008.

Low temperature tunneling magnetoresistance on (La,Sr)MnO[sub 3]/Co junctions with organic spacer layers

H. Vinzelberg, J. Schumann, D. Elefant, R. B. Gangineni, J. Thomas et al.
This paper concerns with giant magnetoresistance (MR) effects in organic spin valves, which are realized as layered (La,Sr)MnO (LSMO)-based junctions with tris-(8, hydroxyquinoline) aluminum (Alq)-spacer and ferromagnetic top layers. The experimental work was focused on the understanding of the tran ... [J. Appl. Phys. 103, 093720 (2008)] published Tue May 13, 2008.

Dependence of temperature and self-heating on electron mobility in ultrathin body silicon-on-insulator n-metal-oxide-semiconductor field-effect transistors

Tae-Hun Shim, Seong-Je Kim, Gon-Sub Lee, Kwan-Su Kim, Won-Ju Cho et al.
We investigated the dependence of temperature and self-heating on electron mobility in ultrathin body fully depleted silicon-on-insulator n-metal-oxide-semiconductor field-effect transistors as a function of silicon thickness by analyzing their electron states and electrical characteristics. We foun ... [J. Appl. Phys. 103, 094522 (2008)] published Tue May 13, 2008.

Magnetism in Gd--W films

Giovana Z. Gadioli, Francisco P. Rouxinol, Rogerio V. Gelamo, Adenilson O. dos Santos, Lisandro P. Cardoso et al.
Vapor condensation techniques are useful to prepare magnetic alloys whose components have low or even negligible equilibrium mutual solubility. In this work, one of these techniquessputteringwas used to obtain GdW alloys whose magnetic properties were investigated as a function of the Gd atomic conc ... [J. Appl. Phys. 103, 093916 (2008)] published Tue May 13, 2008.

Excitation wavelength dependence of the visible photoluminescence from amorphous ZnO granular films

W. C. Zhang, X. L. Wu, H. T. Chen, J. Zhu, and G. S. Huang
Amorphous ZnO granular films were fabricated by anodizing zinc sheet in 0.5M oxalic acid solution under direct current voltage. The photoluminescence spectrum of the as-anodized sample shows a very broad visible emission band, which can be Gaussian divided into two subbands at 525 and 600 nm. Based ... [J. Appl. Phys. 103, 093718 (2008)] published Tue May 13, 2008.

Computer simulation of ferroelectric domain structures in epitaxial BiFeO[sub 3] thin films

J. X. Zhang, Y. L. Li, S. Choudhury, L. Q. Chen, Y. H. Chu et al.
Ferroelectric domain structures of (001), (101), and (111) oriented epitaxial BiFeO thin films were studied by using the phase-field approach. Long-range elastic and electrostatic interactions were taken into account. The effects of various types of substrate constraint on the domain morphologies we ... [J. Appl. Phys. 103, 094111 (2008)] published Tue May 13, 2008.

Mapping exciton quenching in photovoltaic-applicable polymer blends using time-resolved scanning near-field optical microscopy

A. Cadby, G. Khalil, A. M. Fox, and D. G. Lidzey
We have used time-resolved scanning near-field microscopy to image the fluorescence decay lifetime across a phase-separated blend of the photovoltaic-applicable polymers poly(9,9-dioctylfluorene-alt-benzothiadiazole) (F8BT) and poly(9,9-dioctylfluorene-alt-bis- N,N-(4-butylphenyl)-bis-N,N-phenyl-1,4 ... [J. Appl. Phys. 103, 093715 (2008)] published Tue May 13, 2008.

Optical modeling of a folded organic solar cell

Viktor Andersson, Kristofer Tvingstedt, and Olle Inganas
The optical behavior of a reflective tandem solar cell (V cell) is modeled by means of finite element method (FEM) simulations. The absorption of solar light in the active material as well as in both electrode layers is calculated. The FEM solves the electromagnetic wave equation on the entire defin ... [J. Appl. Phys. 103, 094520 (2008)] published Tue May 13, 2008.

Anisotropy of weak light scattering in thin opal films

Sergei G. Romanov
The forward and backward light scattering that accompanied the almost ballistic light propagation in opal-based three-dimensional photonic crystal (PhC) has been experimentally studied. The light path memory and the high anisotropy of scattering have been associated with low-order scattering at larg ... [J. Appl. Phys. 103, 093117 (2008)] published Tue May 13, 2008.

Electrical properties of A/B-site substituted Ni-deficient La(Ni[sub 0.6]Fe[sub 0.3])O[sub 3] perovskites with A = Ag[sup +], Pb[sup 2+], Nd[sup 3+] and B = Mn[sup 3+], Ga[sup 3+]

Chang-Yi Chou, N. Kaurav, Yung-Kang Kuo, and Dong-Hau Kuo
We report the structural and electron transport properties of a series of compounds where A/B-site substituted Ni-deficient La(NiFe)O compounds with A=Ag, Pb, Nd and B=Mn, Ga have been synthesized by a chemical route. Electrical resistivity was used as an indicator to explore the response of La(NiFe ... [J. Appl. Phys. 103, 093716 (2008)] published Tue May 13, 2008.

Sensitive detection of weak absorption signals in photoacoustic spectroscopy by using derivative spectroscopy and wavelet transform

Jincun Zheng, Zhilie Tang, Yongheng He, and Lina Guo
This report presents a practical analytical method of photoacoustic (PA) spectroscopy that is based on wavelet transform (WT) and the first-derivative PA spectrum. An experimental setup is specially designed to obtain the first-derivative spectrum, which aims to identify some unnoticeable absorption ... [J. Appl. Phys. 103, 093116 (2008)] published Tue May 13, 2008.

Thermal stability of sputtered Cu films with nanoscale growth twins

O. Anderoglu, A. Misra, H. Wang, and X. Zhang
We have investigated the thermal stability of sputter-deposited Cu thin films with a high density of nanoscale growth twins by using high-vacuum annealing up to 800 degrees C for 1 h. Average twin lamella thickness gradually increased from approximately 4 nm for as-deposited films to slightly less ... [J. Appl. Phys. 103, 094322 (2008)] published Tue May 13, 2008.

Fabrication and characterization of metal-ferroelectric (PbZr[sub 0.53]Ti[sub 0.47]O[sub 3])-Insulator (Y[sub 2]O[sub 3])-semiconductor field effect transistors for nonvolatile memory applications

Wen-Chieh Shih, Pi-Chun Juan, and Joseph Ya-min Lee
Metal-ferroelectric-insulator-semiconductor (MFIS) field effect transistors with Pb(Zr,Ti)O (PZT) ferroelectric layer and yttrium oxide YO insulator layer were fabricated. The maximum C-V memory window of 1.5 V was obtained at a sweep voltage of 8 V. The dominating conduction mechanism through the ... [J. Appl. Phys. 103, 094110 (2008)] published Tue May 13, 2008.

Density and concentration fluctuations in SiO[sub 2]--GeO[sub 2] optical fiber glass investigated by small angle x-ray scattering

R. Le Parc, B. Champagnon, C. Levelut, V. Martinez, L. David et al.
Density and concentration fluctuations have been investigated in a 3 mol % GeO doped silica glass as a function of the fictive temperature (the temperature at which the structure of the supercooled liquid has been frozen-in to form the glass) by small angle x-ray scattering measurements. The fluct ... [J. Appl. Phys. 103, 094917 (2008)] published Tue May 13, 2008.

Laser-induced self-organization in silicon-germanium thin films

M. Weizman, N. H. Nickel, I. Sieber, and B. Yan
We report on the formation of self-organized structures in thin films of silicon-germanium (SiGe) with 0.3

Nanoporous alumina enhanced surface plasmon resonance sensors

Alexandros G. Koutsioubas, Nikolaos Spiliopoulos, Dimitris Anastassopoulos, Alexandros A. Vradis, and George D. Priftis
The signal enhancement of an easy to fabricate, nanoporous alumina assisted surface plasmon resonance (SPR) sensor is investigated. It is theoretically shown that the presence of a thin (under 200 nm) porous alumina layer on top of an aluminum film supporting the surface plasmons, may significantly ... [J. Appl. Phys. 103, 094521 (2008)] published Tue May 13, 2008.

Effect of Mn doping on the electric and dielectric properties of ZnO epitaxial films

T. Oshio, K. Masuko, A. Ashida, T. Yoshimura, and N. Fujimura
The Mn doping effects on the electric and dielectric properties of ZnO epitaxial films were studied. To optimize the stoichiometry of undoped ZnO film prepared by pulsed laser deposition, we evaluated the intensity ratio of the optical emission from excited oxygen atoms (O) and excited zinc atoms (Z ... [J. Appl. Phys. 103, 093717 (2008)] published Tue May 13, 2008.

Size and frequency dependence of effective thermal conductivity in nanosystems

F. X. Alvarez and D. Jou
A single phenomenological expression is proposed to describe thermal transport in a wide variety of nanoscale devices. Size and frequency dependence is studied for some nanosystems from the diffusive to the ballistic regimes. In a single expression we obtain the effective thermal conductivity of cro ... [J. Appl. Phys. 103, 094321 (2008)] published Tue May 13, 2008.

Laser oscillation in a highly anisotropic organic crystal with a refractive index of 4.0

Takeshi Yamao, Kazunori Yamamoto, Yuki Taniguchi, Tomoharu Miki, and Shu Hotta
We have determined a refractive index of an organic single crystal of a thiophene/phenylene co-oligomer in its laser oscillation wavenumbers. We estimated the refractive index to be 4.0 on the basis of the mode intervals of the well-resolved longitudinal multimodes that are highly polarized along th ... [J. Appl. Phys. 103, 093115 (2008)] published Tue May 13, 2008.

Structural and optical properties of vertically stacked triple InAs dot-in-well structure

G. Raino, A. Salhi, V. Tasco, M. De Vittorio, A. Passaseo et al.
The authors report a detailed investigation of the structural and optical properties of vertically stacked InAs quantum dots embedded in an (In,Ga)As quantum well by means of transmission electron microscopy and time resolved photoluminescence based on the upconversion technique. By comparing the op ... [J. Appl. Phys. 103, 096107 (2008)] published Mon May 12, 2008.

Properties of GaP(001) surfaces thermally annealed in dry N[sub 2] atmosphere

Hiroshi Rokugawa and Sadao Adachi
Isochronal annealing behaviors of GaP(001) surfaces in dry N atmosphere for t=20 min have been studied by using spectroellipsometry (SE), optical microscopy, scanning electron microscopy (SEM), ex situ atomic force microscopy (AFM), and x-ray photoelectron spectroscopy (XPS). The SE data suggest th ... [J. Appl. Phys. 103, 093535 (2008)] published Mon May 12, 2008.

Interlevel transitions and two-photon processes in Ge/Si quantum dot photocurrent

E. Finkman, N. Shuall, A. Vardi, V. Le Thanh, and S. E. Schacham
Photocurrent spectra due to interlevel transitions of holes in Ge/Si quantum dots show several peaks in the range of 60300 meV, which superlinearly increase with bias, indicating release of carriers by tunneling. The relative peak intensity drastically changes with applied voltage, its polarity, and ... [J. Appl. Phys. 103, 093114 (2008)] published Mon May 12, 2008.

Structure properties of BiFeO[sub 3] films studied by micro-Raman scattering

Y. Yang, J. Y. Sun, K. Zhu, Y. L. Liu, and L. Wan
BiFeO (BFO) films deposited on SrTiO (001) substrates and on LaNiO-coated SrTiO (001) substrates with different annealing ambiences of oxygen and nitrogen were studied by using micro-Raman spectroscopy and x-ray diffraction (XRD). XRD showed that the films are in single-phase with rhombohedral struc ... [J. Appl. Phys. 103, 093532 (2008)] published Mon May 12, 2008.

Electronic structure of a laterally graded ZrO[sub 2]--TiO[sub 2] film on Si(100) prepared by metal-organic chemical vapor deposition in ultrahigh vacuum

J. H. Richter, P. G. Karlsson, and A. Sandell
A TiOZrO film with laterally graded stoichiometry has been prepared by metal-organic chemical vapor deposition in ultrahigh vacuum. The film was characterized in situ using synchrotron radiation photoelectron spectroscopy (PES) and x-ray absorption spectroscopy. PES depth profiling clearly shows tha ... [J. Appl. Phys. 103, 094109 (2008)] published Mon May 12, 2008.

A study on the transmission of picosecond ultrasonic waves in Si/Mo superlattices

Wei-I Kuo, En-Yea Pan, and Nen-Wen Pu
We have performed theoretical and experimental studies on the optical generation and transmission of picosecond ultrasonic pulses in a-Si/Mo superlattices using ultrafast lasers. The pulse shapes and spectra of collectively excited folded phonon waves were analyzed. Calculations show that the picose ... [J. Appl. Phys. 103, 093533 (2008)] published Mon May 12, 2008.

Conductor grid optimization for luminance loss reduction in organic light emitting diodes

Kristiaan Neyts, Alfonso Real, Matthias Marescaux, Saso Mladenovski, and Jeroen Beeckman
The recently increased efficiency of organic light emitting devices (OLED) brings lighting applications within reach. If the area of the OLED is of the order a cm, voltage and brightness losses related to the square resistance of the transparent electrode become important. The homogeneity of the vol ... [J. Appl. Phys. 103, 093113 (2008)] published Mon May 12, 2008.

Brightness enhancement method for a high-intensity positron beam produced by an electron accelerator

Nagayasu Oshima, Ryoichi Suzuki, Toshiyuki Ohdaira, Atsushi Kinomura, Takamitsu Narumi et al.
A method for enhancing the brightness of an intense slow positron beam produced by an electron linear accelerator (LINAC) in order to obtain an intense positron microbeam was developed. The developed brightness enhancement system is simple and consists only of a few beam optics and a transmission re ... [J. Appl. Phys. 103, 094916 (2008)] published Mon May 12, 2008.

Formation of dysprosium silicide nanowires on Si(557) with two-dimensional electronic structure

M. Wanke, K. Loser, G. Pruskil, and M. Dahne
The self-organized growth of dysprosium silicide nanowires on Si(557) has been studied using scanning tunneling microcopy and angle-resolved photoelectron spectroscopy. The nanowires grow on the (111) facets of the Si(557) surface with lengths exceeding 1000 nm and widths of 35 nm. Their metallic el ... [J. Appl. Phys. 103, 094319 (2008)] published Mon May 12, 2008.

Erratum: ``All-ion accelerators: An injector-free synchrotron'' [J. Appl. Phys. 101, 063304 (2007)]

Ken Takayama, Yoshio Arakida, Taiki Iwashita, Yoshito Shimosaki, Tanuja Dixit et al.
... [J. Appl. Phys. 103, 099903 (2008)] published Mon May 12, 2008.

Origin of current oscillations in a polymeric electrochemically controlled element

Anteo Smerieri, Victor Erokhin, and Marco P. Fontana
We present a model for describing electrical properties of an electrochemically controlled heterojunction between a conducting polymer (polyaniline) and a solid electrolyte (lithium salt doped polyethylene oxide). In particular, the difference in the kinetics of the conductivity variation for differ ... [J. Appl. Phys. 103, 094517 (2008)] published Mon May 12, 2008.

Graded wavelength one-dimensional photonic crystal reveals spectral characteristics of enhanced fluorescence

Patrick C. Mathias, Nikhil Ganesh, Wei Zhang, and Brian T. Cunningham
One-dimensional photonic crystal (PC) slabs are capable of enhancing the excitation of fluorescent material adsorbed on their surface. In this report, we demonstrate and verify by electromagnetic computer simulations that resonant leaky modes spectrally overlapping the laser wavelength used for fluo ... [J. Appl. Phys. 103, 094320 (2008)] published Mon May 12, 2008.

Thermal growth and structural and optical characterization of indium tin oxide nanopyramids, nanoislands, and tubes

D. Maestre, A. Cremades, J. Piqueras, and L. Gregoratti
In-doped SnO microtubes as well as Sn-doped InO (ITO) nano- and microislands have been grown by thermal treatment of compacted SnOInO powders under argon flow at 1350 degrees C in a catalyst-free process. The SnO tubes contain about 1 at. % of In, even when the In content in the starting mixture w ... [J. Appl. Phys. 103, 093531 (2008)] published Mon May 12, 2008.

Two-dimensional electron gas density in Al[sub 1 - x]In[sub x]N/AlN/GaN heterostructures (0.03 <= x <= 0.23)

M. Gonschorek, J.-F. Carlin, E. Feltin, M. A. Py, N. Grandjean et al.
Compared to the AlGaN alloy, which can only be grown under tensile strain on GaN, the AlInN alloy is predicted by Vegard's law to be lattice-matched (LM) on fully relaxed GaN templates for an indium content of ~17.5%, i.e., it can be grown either tensely or compressively on GaN. The effect of strain ... [J. Appl. Phys. 103, 093714 (2008)] published Mon May 12, 2008.

Field emission of bismuth sulfide upright-standing platelets

T. Ganesh, Jungwoo Lee, Rajaram S. Mane, Whi Kun Yi, B. N. Pawar et al.
Indium-tin-oxide substrate-supported chemically synthesized bismuth sulfide upright-standing platelets of micron-size height and nanometer-size width are explored for the field emission. Bismuth sulfide upright-standing platelets electrode shows a turn-on field of 2.83 V/[mu]m at a current density ... [J. Appl. Phys. 103, 096108 (2008)] published Mon May 12, 2008.

Improvement of n-channel metal-oxide-semiconductor transistors by tensile stress despite increase in both on and subthreshold off currents

Peizhen Yang, W. S. Lau, Tiong Liang Ng, V. Ho, C. H. Loh et al.
We found that tensile stress actually increases both the on current and the subthreshold off current for n-channel metal-oxide-semiconductor transistors because of an increase in mobility. Our theory is that stress engineering works because the increase in the subthreshold off current can be easily ... [J. Appl. Phys. 103, 094518 (2008)] published Mon May 12, 2008.

Enhanced Hall effect in Fe[sub x]Ge[sub 1 - x] nanocomposite films

W. B. Mi, Y. W. Liu, E. Y. Jiang, and H. L. Bai
Enhanced Hall effect has been observed in the FeGe nanocomposite films composed of nanoscale Fe grains embedded in amorphous Ge matrix. The Fe grain size, the saturation magnetization, and the interparticle interaction increase with increasing Fe atomic fraction x. The transport mechanism of the fil ... [J. Appl. Phys. 103, 093713 (2008)] published Mon May 12, 2008.

Effect of silicon interstitials on Cu precipitation in n-type Czochralski silicon

Weiyan Wang, Deren Yang, Xiangyang Ma, and Duanlin Que
The effect of silicon interstitials induced by the prior thermal oxidation at 900 degrees C for 250 min on copper (Cu) precipitation in n-type silicon has been investigated by means of transmission electron microscopy and optical microscopy. For the sample without the prior thermal oxidation, the ... [J. Appl. Phys. 103, 093534 (2008)] published Mon May 12, 2008.

Realization of ambipolar pentacene thin film transistors through dual interfacial engineering

Chuan-Yi Yang, Shiau-Shin Cheng, Chun-Wei Ou, You-Che Chuang, Meng-Chyi Wu et al.
Ambipolar conduction of a pentacene-based field-effect transistor can be attributed to dual interface engineering, which occurs at the dielectric/semiconductor interface and electrode/semiconductor interface. While the former was realized by utilizing a hydroxyl-free gate dielectric, the latter was ... [J. Appl. Phys. 103, 094519 (2008)] published Mon May 12, 2008.

Intensity analysis and crystal-field modeling of Ho[sup 3+] in KPb[sub 2]Cl[sub 5] host

Dhiraj K. Sardar, Sree R. Chandrasekharan, Kelly L. Nash, John B. Gruber, Arnold Burger et al.
Optical absorption and emission intensities are investigated for Ho doped into single-crystal KPbCl. Room temperature absorption spectra of Ho(4f), representing transitions from I to excited multiplet manifolds observed between 400 and 2100 nm, have been analyzed using the JuddOfelt (JO) model to ob ... [J. Appl. Phys. 103, 093112 (2008)] published Mon May 12, 2008.

Terahertz Gunn-like oscillations in InGaAs/InAlAs planar diodes

S. Perez, T. Gonzalez, D. Pardo, and J. Mateos
A microscopic analysis of self-generated terahertz current oscillations that take place in planar InAlAs/InGaAs slot diodes operating under dc bias is presented. An ensemble Monte Carlo simulation is used for the calculations. The onset of the oscillations is thresholdlike, for drain-source voltages ... [J. Appl. Phys. 103, 094516 (2008)] published Fri May 9, 2008.

The relationship between local order, long range order, and sub-band-gap defects in hafnium oxide and hafnium silicate films

D. H. Hill, R. A. Bartynski, N. V. Nguyen, Albert C. Davydov, Deane Chandler-Horowitz et al.
We have measured x-ray absorption spectra (XAS) at the oxygen K edge for hafnium oxide (HfO) films grown by chemical vapor deposition (CVD) and atomic layer deposition (ALD), as well as for hafnium silicate (HfSiO) films grown by CVD. The XAS results are compared to x-ray diffraction (XRD) and spect ... [J. Appl. Phys. 103, 093712 (2008)] published Fri May 9, 2008.

Surface-plasmon-enhanced frequency upconversion in Pr[sup 3+] doped tellurium-oxide glasses containing silver nanoparticles

Vineet Kumar Rai, Leonardo de S. Menezes, Cid B. de Araujo, Luciana R. P. Kassab, Davinson M. da Silva et al.
A frequency upconversion process in Pr doped TeOZnO glasses containing silver nanoparticles is studied under excitation with a nanosecond laser operating at 590 nm, in resonance with the H-->D transition. The excited Pr ions exchange energy in the presence of the nanoparticles, originating efficient ... [J. Appl. Phys. 103, 093526 (2008)] published Fri May 9, 2008.

The effect of wafer curvature on x-ray rocking curves from gallium nitride films

M. A. Moram, M. E. Vickers, M. J. Kappers, and C. J. Humphreys
The full width at half maximum (FWHM) of x-ray rocking curves is often used as a measure of the crystalline quality of thin films. In this paper, the effects of wafer curvature on the x-ray rocking curves (omega-scans) obtained from a 2 in. 0001-oriented sapphire wafer and an epitaxial 0001-oriente ... [J. Appl. Phys. 103, 093528 (2008)] published Fri May 9, 2008.

Anomalous temperature-dependent exchange bias in Fe films deposited on Si substrates with the native oxide layer

Wenhong Wang, Fumiyoshi Takano, Masato Takenaka, Hiro Akinaga, and Hironori Ofuchi
The temperature dependence of the exchange bias has been investigated in Fe films deposited on the Si substrates with the native oxidize layer. A crossover from negative to positive exchange bias has been observed with increasing temperature at 30 K, accompanied with the maximum of the coercivity. T ... [J. Appl. Phys. 103, 093914 (2008)] published Fri May 9, 2008.

Structural and morphological properties of GaN buffer layers grown by ammonia molecular beam epitaxy on SiC substrates for AlGaN/GaN high electron mobility transistors

A. L. Corrion, C. Poblenz, F. Wu, and J. S. Speck
The impact of growth conditions on the surface morphology and structural properties of ammonia molecular beam epitaxy GaN buffers layers on SiC substrates was investigated. The threading dislocation (TD) density was found to decrease with decreasing NH:Ga flux ratio, which corresponded to an increas ... [J. Appl. Phys. 103, 093529 (2008)] published Fri May 9, 2008.

Femtosecond pulsed laser ablation dynamics and ablation morphology of nickel based superalloy CMSX-4

Joel P. McDonald, Shuwei Ma, Tresa M. Pollock, Steven M. Yalisove, and John A. Nees
Pump-probe shadowgraphic imaging of single pulse femtosecond laser ablation was performed to investigate the dynamics of material removal during femtosecond laser machining of the intermetallic superalloy CMSX-4. Time-resolved shadowgraphic images were collected, which showed the presence of an expa ... [J. Appl. Phys. 103, 093111 (2008)] published Fri May 9, 2008.

The potential and device physics of interdigitated thin-film solar cells

Wyatt K. Metzger
The device physics of thin-film solar cells with interdigitated p-n junctions is examined for a range of spatial sizes, band offsets, and material parameters. The results are illustrated by focusing on recent nanoscale concepts for Cu(In,Ga)Se solar cells. Ideally, nanoscale interdigitated junctions ... [J. Appl. Phys. 103, 094515 (2008)] published Fri May 9, 2008.

Magnetization behavior of ordered and high density Co nanowire arrays with varying aspect ratio

G. Kartopu, O. Yalcin, M. Es-Souni, and A. C. Basaran
Densely packed and ordered cobalt nanowire (NW) arrays with aspect ratios (wire length/diameter) varying between 5 and 250 have been fabricated via electrodeposition into alumina templates. The wire length and diameter were controlled by monitoring the total deposited charge or by adjusting the temp ... [J. Appl. Phys. 103, 093915 (2008)] published Fri May 9, 2008.

Impact of feature-size dependent etching on the optical properties of photonic crystal devices

A. Berrier, R. Ferrini, A. Talneau, R. Houdre, and S. Anand
Feature size dependence in Ar/Cl chemically assisted ion beam etching of InP-based photonic crystals (PhCs) and its influence on the optical properties of PhC devices operating in the band gap are investigated. The analysis of the measured quality factors, the determined mirror reflectivities, and l ... [J. Appl. Phys. 103, 096106 (2008)] published Fri May 9, 2008.

Nanogranular structures formed by combinatorial control processing of size-selected metal nanoparticles

Seung Hun Huh, Doh Hyung Riu, Chang Yeoul Kim, Yasutomo Naono, Tsuneyuki Nakamura et al.
Nanogranular films and lines, which are composed of size-selected Au, Ni, and Pt nanoparticles (NPs) and which exhibit an intermediate structure between that of the individual NPs and that of polycrystalline ones, were produced by a fully physical process. By using a combination of techniques such a ... [J. Appl. Phys. 103, 094317 (2008)] published Fri May 9, 2008.

Correlation between luminescent properties and local coordination environment for erbium dopant in yttrium oxide nanotubes

Yuanbing Mao, John Bargar, Michael Toney, and Jane P. Chang
The local dopant coordination environment and its effect on the photoluminescent (PL) spectral features of erbium-doped yttrium oxide nanotubes (NTs) were probed by synchrotron-based x-ray diffraction (XRD), x-ray absorption near-edge spectroscopy (XANES), and extended x-ray absorption fine structur ... [J. Appl. Phys. 103, 094316 (2008)] published Fri May 9, 2008.

Anomalous lattice relaxation mechanics in ZnO/SiC heterostructure

Almamun Ashrafi and Yusaburo Segawa
Anomalous lattice relaxation mechanics in ZnO epitaxy deposited on 6H-SiC substrates has been addressed. Thickness-dependent ZnO epitaxy showed that the lattice/strain relaxes into two steps for the layer thicknesses of (i) 1020 nm, after overcoming the critical thickness of <6 nm and (ii) 4801000 ... [J. Appl. Phys. 103, 093527 (2008)] published Fri May 9, 2008.

Extended longitudinal vector and Bragg magneto-optic Kerr effect for the determination of the chirality distribution in magnetic vortices

Min-Sang Lee, Andreas Westphalen, Arndt Remhof, Alexandra Schumann, and Harmut Zabel
We have measured longitudinal magneto-optic Kerr effect (MOKE) for off-specular beams diffracted by a square array of Permalloy nanodots outside the plane of incidence and found that only the measurements performed outside the plane of incidence are sensitive to the distribution of rotational sense ... [J. Appl. Phys. 103, 093913 (2008)] published Fri May 9, 2008.

Wireless drive of a piezoelectric plate by capacitorlike structure in electric resonance with an inductor

Satyanarayan Bhuyan, Junhui Hu, and Chang Qing Sun
A new technique of wirelessly transmitting electric energy to piezoelectric components is explored. In the design, an ac electric field is focused to a piezoelectric plate placed between plate-shaped live and needle ground electrodes which form a capacitorlike electric field generator in series with ... [J. Appl. Phys. 103, 094915 (2008)] published Fri May 9, 2008.

Magnetic-field-enhanced synthesis of single-wall carbon nanotubes in arc discharge

Michael Keidar, Igor Levchenko, Tamir Arbel, Myriam Alexander, Anthony M. Waas et al.
The ability to control the properties of single-wall nanotubes (SWNTs) produced in the arc discharge is important for many practical applications. Our experiments suggest that the length of SWNTs significantly increases (up to 4000 nm), along with the purity of the carbon deposit, when the magnetic ... [J. Appl. Phys. 103, 094318 (2008)] published Fri May 9, 2008.

Influence of synthetic nucleation layers on the microstructure, magnetic properties, and recording performance of CoCrPt--SiO[sub 2] perpendicular recording media

Kumar Srinivasan, Seng Kai Wong, S. N. Piramanayagam, and Yew Seng Kay
The performance of CoCrPtSiO perpendicular recording media, which incorporate synthetic nucleation layers for inducing grain size control, was evaluated with regard to the crystallographic, microstructural, magnetic, interfacial, and recording properties. The media structure consisted of a 14 nm thi ... [J. Appl. Phys. 103, 093912 (2008)] published Fri May 9, 2008.

The relation between shock-state particle velocity and free surface velocity: A molecular dynamics study on single crystal Cu and silica glass

Sheng-Nian Luo, Li-Bo Han, Yun Xie, Qi An, Lianqing Zheng et al.
We investigate the ratio R of the free surface velocity to the shock-state particle velocity during shock wave loading with molecular dynamics simulations on two representative solids, single crystal Cu, and silica glass. The free surface velocity is obtained as a function of the particle velocity b ... [J. Appl. Phys. 103, 093530 (2008)] published Fri May 9, 2008.

Channel-drop filters in three-dimensional woodpile photonic crystals

Rong-Juan Liu, Zhi-Yuan Li, Zhi-Fang Feng, Bing-Ying Cheng, and Dao-Zhong Zhang
Optical waveguides are characterized by high-efficiency transmission of electromagnetic (EM) waves and optical cavities have frequency selective property. The combination of optical waveguides and cavities can result in a large amount of devices in optical integrated circuit, among which a channel-d ... [J. Appl. Phys. 103, 094514 (2008)] published Fri May 9, 2008.

Measurement of the junction temperature in high-power light-emitting diodes from the high-energy wing of the electroluminescence band

Z. Vaitonis, P. Vitta, and A. Zukauskas
By using pulsed driving currents with a small duty cycle, the high-energy wing of the electroluminescence band in AlGaInP and InGaN high-power light-emitting diodes (LEDs) was calibrated to measure the junction temperature in the range of 223358 K. In a red AlGaInP LED with a thick active layer, an ... [J. Appl. Phys. 103, 093110 (2008)] published Fri May 9, 2008.

Ab initio study of the optical phonons in one-dimensional antiferromagnet Ca[sub 2]CuO[sub 3]

Nam Nhat Hoang, Thu Hang Nguyen, and Chau Nguyen
We present the cluster-model ab initio study of the optical phonons in the one-dimensional antiferromagnet CaCuO based on the HartreeFock self-consistent field calculation with the 3-21G basis set. The obtained results showed very good agreement with the observed data. The CuO bands generally showed ... [J. Appl. Phys. 103, 093524 (2008)] published Thu May 8, 2008.

Optical phonon characteristics of incommensurate and commensurate modulated phases of Bi[sub 3]NbO[sub 7] ceramics

Roberto L. Moreira, Franklin M. Matinaga, Ursa Pirnat, Danilo Suvorov, and Anderson Dias
Raman and infrared-reflectivity spectroscopies were used to investigate the optical phonon modes of the cubic-incommensurate and tetragonal-commensurate phases of BiNbO ceramic samples. For both structures, the observed features could be well described by applying the factor-group method to average ... [J. Appl. Phys. 103, 094108 (2008)] published Thu May 8, 2008.

Determining the stress tensor in strained semiconductor structures by using polarized micro-Raman spectroscopy in oblique backscattering configuration

Razvigor Ossikovski, Quang Nguyen, Gennaro Picardi, and Joachim Schreiber
We present a characterization technique for the determination of the stress tensor as well as of the crystallographic orientation of strained semiconductor structures. The technique is based on a polarized oblique incidence micro-Raman experiment in a backscattering configuration. A methodology rela ... [J. Appl. Phys. 103, 093525 (2008)] published Thu May 8, 2008.

The Einstein relation in quantum wires of III-V, ternary, and quaternary materials in the presence of light waves: Simplified theory, relative comparison, and suggestion for experimental determination

K. P. Ghatak, S. Bhattacharya, S. Bhowmik, R. Benedictus, and S. Choudhury
We study the Einstein relation for the diffusivity to mobility ratio (DMR) in quantum wires (QWs) of III-V, ternary, and quaternary materials in the presence of light waves, whose unperturbed energy band structures are defined by the three band model of Kane. It has been found, taking n-InAs, n-InSb ... [J. Appl. Phys. 103, 094314 (2008)] published Thu May 8, 2008.

Spectral and nonlinear optical characteristics of nanocomposites of ZnO--CdS

Litty Irimpan, V. P. N. Nampoori, and P. Radhakrishnan
In this article, we present the spectral and nonlinear optical properties of ZnOCdS nanocomposites prepared by colloidal chemical synthesis. The optical band gap (E) of the material is tunable between 2.62 and 3.84 eV. The emission peaks of ZnOCdS nanocomposites change from 385 to 520 nm almost in p ... [J. Appl. Phys. 103, 094914 (2008)] published Thu May 8, 2008.

Long-wavelength light emission from self-assembled heterojunction quantum dots

Zhiqiang Zhou, Yingqiang Xu, Ruiting Hao, Bao Tang, Zhengwei Ren et al.
The authors report the optical characteristics of GaSb/InAs/GaAs self-assembled heterojunction quantum dots (QDs). With increasing GaSb deposition, the room temperature emission wavelength can be extended to 1.56 [mu]m. The photoluminescence mechanism is considered to be a type-II transition with e ... [J. Appl. Phys. 103, 094315 (2008)] published Thu May 8, 2008.

Strain-induced ferromagnetism enhancement in Co:ZnO films

X. J. Liu, C. Song, F. Zeng, F. Pan, B. He et al.
The structural and ferromagnetic properties of ZnCoO films grown on Si and LiNbO (LNO) substrates have been studied as a function of thickness (15900 nm). The structural characterizations indicate that the c-axis lattice constant and CoO bond length slightly decrease with the increase in film thickn ... [J. Appl. Phys. 103, 093911 (2008)] published Thu May 8, 2008.

A phenomenological model for the reliability of GaAs based heterojunction bipolar transistors

C. P. Lee, F. Chau, B. Lin, M. Kretschmar, and W. Ma
We present a phenomenological model for the lifetime prediction of GaAs based heterojunction bipolar transistors (HBTs). Both thermal activation process and recombination enhanced defect generation process were considered phenomenologically. At high stress temperatures, the lifetime of the transisto ... [J. Appl. Phys. 103, 094512 (2008)] published Thu May 8, 2008.

Measurement of deep states in hole doped organic semiconductors

Debdutta Ray and K. L. Narasimhan
In this paper, we report on the electrical properties of hole doped N,N-diphenyl-N,N-bis(3-methylphenyl)-(1,1-biphenyl)-4,4-diamine and tris(8-hydroxyquinoline) aluminum. Tetrafluorotetracyanoquinodimethane is used as the dopant. From the frequency dependence of the capacitance measurements, we show ... [J. Appl. Phys. 103, 093711 (2008)] published Thu May 8, 2008.

A field evaporation deuterium ion source for neutron generators

Birk Reichenbach, I. Solano, and P. R. Schwoebel
Proof-of-principle experiments have demonstrated an electrostatic field evaporation based deuterium ion source for use in compact, high-output deuterium-tritium neutron generators. The ion source produces principally atomic deuterium and titanium ions. More than 100 ML of deuterated titanium thin fi ... [J. Appl. Phys. 103, 094912 (2008)] published Thu May 8, 2008.

Photoluminescence and surface photovoltage spectroscopy characterization of Zn[sub 1 - x - y]Be[sub x]Mg[sub y]Se mixed crystals

D. O. Dumcenco, H. P. Hsu, Y. S. Huang, F. Firszt, S. Legowski et al.
This paper presents an optical characterization of three Bridgman-grown ZnBeMgSe mixed crystals in the near-band-edge interband transitions using temperature-dependent photoluminescence (PL) in the temperature range of 10300 K and surface photovoltage spectroscopy (SPS) at room temperature. PL spect ... [J. Appl. Phys. 103, 093522 (2008)] published Thu May 8, 2008.

Systematic investigation of the growth and structural properties of FeTiO[sub 3 [plus-minus] delta] epitaxial thin films

E. Popova, B. Warot-Fonrose, H. Ndilimabaka, M. Bibes, N. Keller et al.
An understanding of the thin film structure and properties of ilmenite is crucial for the future study of ilmenite-hematite solid solutions for spintronics applications. Here, we report a systematic study of the FeTiO thin film structure as a function of the deposition parameters during pulsed laser ... [J. Appl. Phys. 103, 093909 (2008)] published Thu May 8, 2008.

Terahertz detection mechanism of inexpensive sensitive glow discharge detectors

D. Rozban, N. S. Kopeika, A. Abramovich, and E. Farber
The detection mechanism of glow discharge plasma, which is derived from direct current gas breakdown, in neon indicator lamps was investigated in the terahertz and microwave regimes. Such devices exhibit high sensitivity to terahertz radiation. Experimental setups at 10, 100, and 250 GHz were carri ... [J. Appl. Phys. 103, 093306 (2008)] published Thu May 8, 2008.

The stochastic dynamics of rectangular and V-shaped atomic force microscope cantilevers in a viscous fluid and near a solid boundary

M. T. Clark and M. R. Paul
Using a thermodynamic approach based upon the fluctuation-dissipation theorem, we quantify the stochastic dynamics of rectangular and V-shaped microscale cantilevers immersed in a viscous fluid. We show that the stochastic cantilever dynamics as measured by the displacement of the cantilever tip or ... [J. Appl. Phys. 103, 094910 (2008)] published Thu May 8, 2008.

Models of water imbibition in untreated and treated porous media validated by quantitative magnetic resonance imaging

M. Gombia, V. Bortolotti, R. J. S. Brown, M. Camaiti, and P. Fantazzini
Fluid imbibition affects almost every activity that directly or indirectly involves porous media, including oil reservoir rocks, soils, building materials, and countless others, including biological materials. In this paper, magnetic resonance imaging (MRI) has been applied to study water imbibition ... [J. Appl. Phys. 103, 094913 (2008)] published Thu May 8, 2008.

Gas detectors for x-ray lasers

K. Tiedtke, J. Feldhaus, U. Hahn, U. Jastrow, T. Nunez et al.
We have developed different types of photodetectors that are based on the photoionization of a gas at a low target density. The almost transparent devices were optimized and tested for online photon diagnostics at current and future x-ray free-electron laser facilities on a shot-to-shot basis with a ... [J. Appl. Phys. 103, 094511 (2008)] published Thu May 8, 2008.

Effect of anisotropic strain on the charge ordering transition in manganite films

Y. Z. Chen, J. R. Sun, S. Liang, W. M. Lv, B. G. Shen et al.
The substrate induced anisotropic strain was found to have a significant effect on the charge ordering (CO) transition and surface morphology in BiCaMnO films deposited on (110)- and (111)-oriented SrTiO substrates. Effects of film thickness t on the CO transition were further studied. The CO transi ... [J. Appl. Phys. 103, 096105 (2008)] published Thu May 8, 2008.

Temperature-dependent optical constants and birefringence of nematic liquid crystal 5CB in the terahertz frequency range

Ru-Pin Pan, Cho-Fan Hsieh, Ci-Ling Pan, and Chao-Yuan Chen
We have measured the frequency dependence and temperature dependence of the optical constants of a liquid crystal 4-n-pentyl-4-cyanobiphenyl (5CB) in both nematic and isotropic phases by using terahertz time-domain spectroscopy. The extinction coefficient of 5CB is less than 0.02 and without sharp a ... [J. Appl. Phys. 103, 093523 (2008)] published Thu May 8, 2008.

Magnetization reversal of Co/Cu/Co elliptical elements studied by in-field magnetic force microscope and micromagnetic simulation

T. Wang, W. L. Pei, Y. Fu, T. Washiya, T. Hasegawa et al.
The magnetization reversal process of 10 nm Au/5 nm Co/6 nm Cu/30 nm Co elements with a 100 nm x 200 nm elliptical shape was studied using a magnetic force microscope (MFM) with a variable in-plane applied field and a high coercivity tip. MFM observations showed that the ground states of top and b ... [J. Appl. Phys. 103, 093910 (2008)] published Thu May 8, 2008.

A comprehensive analytical on-current model for polycrystalline silicon thin film transistors based on effective channel mobility

Han Hao, Mingxiang Wang, Bo Zhang, Xuejie Shi, and Man Wong
A comprehensive analytical ON-state drain current model for poly-Si thin film transistors (TFTs) is developed to accurately fit both transfer and output characteristics of either low or high temperature processed poly-Si TFTs in both n- and p-types, with the same unified analytical form. The model i ... [J. Appl. Phys. 103, 094513 (2008)] published Thu May 8, 2008.

Threshold criteria for undervoltage breakdown

James E. Cooley and Edgar Y. Choueiri
The conditions under which an externally supplied pulse of electrons will induce breakdown in an undervoltaged, low-gain discharge gap are experimentally and theoretically explored. The minimum number of injected electrons required to achieve breakdown in a parallel-plate gap is measured in argon at ... [J. Appl. Phys. 103, 093305 (2008)] published Thu May 8, 2008.

Determination of the magnetic moment and geometrical dimensions of the magnetotactic bacteria using an optical scattering method

Petre Catalin Logofatu, Ioan Ardelean, Dan Apostol, Iuliana Iordache, Mihaela Bojan et al.
We adapted an experimental technique for characterizing the magnetotactic bacteria and simplified it by transferring the burden to literal and numerical computation, which is an advantageous tradeoff. In a magnetic field the bacteria tend to orient their magnetic axes along the direction of the magn ... [J. Appl. Phys. 103, 094911 (2008)] published Wed May 7, 2008.

Phonon strain shift coefficients in Si[sub 1 - x]Ge[sub x] alloys

F. Pezzoli, E. Bonera, E. Grilli, M. Guzzi, S. Sanguinetti et al.
A comprehensive study of the biaxial strain-induced shift of the SiGe Raman active phonon modes is presented. High-resolution Raman measurements of SiGe/Si heterostructures have been compared to x-ray diffraction data. Our approach, unlike previous works, is effective to decouple and quantify separa ... [J. Appl. Phys. 103, 093521 (2008)] published Wed May 7, 2008.

Charge-sensitive infrared phototransistors: Characterization by an all-cryogenic spectrometer

Takeji Ueda, Zhenghua An, Kazuhiko Hirakawa, and Susumu Komiyama
Charge-sensitive infrared phototransistors (CSIPs) with a 16 x 4 [mu]m active area, which are fabricated in a GaAs/AlGaAs double-quantum-well structure, are studied with an all-cryogenic spectrometer operated at 4.2 K. Extremely low level of background radiation makes reliable determination of dete ... [J. Appl. Phys. 103, 093109 (2008)] published Wed May 7, 2008.

Organization of liquid crystals on submicron scale topographic patterns with fourfold symmetry prepared by thiolene photopolymerization-based nanoimprint lithography

Y. W. Yi, V. Khire, C. N. Bowman, J. E. Maclennan, and N. A. Clark
The organization of nematic liquid crystals in thin cells with one surface topographically patterned by thiolene step and flash nanoimprint lithography was studied using depolarizing transmission light microscopy. Planar bistable organization was observed for 2 and 4 [mu]m wide square grid patterns ... [J. Appl. Phys. 103, 093518 (2008)] published Wed May 7, 2008.

X-ray photoelectron studies of clean and oxidized alpha -GeTe(111) surfaces

L. V. Yashina, R. Puttner, V. S. Neudachina, T. S. Zyubina, V. I. Shtanov et al.
Clean and oxidized (1010 L of O) surfaces of alpha-GeTe have been investigated with x-ray photoelectron spectroscopy by using the synchrotron radiation facility BESSY II as well as an Al Kalpha source. To understand the first steps of oxidation, complementary quantum chemical calculations were perf ... [J. Appl. Phys. 103, 094909 (2008)] published Wed May 7, 2008.

Flux-line cutting in rotating type-II superconductors in parallel geometry

C. Romero-Salazar and O. A. Hernandez-Flores
Experimental results of a type-II superconductor, undergoing slow oscillations in a static magnetic field, have been theoretically investigated. The theoretical description considers the occurrence of flux-line cutting since the critical currents have a parallel component to the magnetic induction B ... [J. Appl. Phys. 103, 093907 (2008)] published Wed May 7, 2008.

Equilibrium of an elastically confined liquid drop

Hyuk-Min Kwon, Ho-Young Kim, Jerome Puell, and L. Mahadevan
When a liquid drop is confined between an elastic plate and a rigid substrate, it spreads spontaneously due to the effects of interfacial forces, eventually reaching an equilibrium shape determined by the balance between elastic and capillary effects. We provide an analytical theory for the static s ... [J. Appl. Phys. 103, 093519 (2008)] published Wed May 7, 2008.

Dependence of plasmon polaritons on the thickness of indium tin oxide thin films

C. Rhodes, M. Cerruti, A. Efremenko, M. Losego, D. E. Aspnes et al.
The evolution of polariton features with increasing thickness in p-polarized (TM) reflectance spectra of indium tin oxide (ITO) thin films deposited on BK7 glass reveals the nature of plasmons in conducting thin films without interference from band-to-band transitions or the tendency of very thin fi ... [J. Appl. Phys. 103, 093108 (2008)] published Wed May 7, 2008.

Effect of Ir--Mn composition on exchange bias and thermal stability of spin valves with nano-oxide layers

Y. F. Liu, J. W. Cai, W. Y. Lai, and G. H. Yu
The IrMn bottom-pinned spin valves with nano-oxide layers (NOLs), Ta/NiFe/IrMn/CoFe/NOL/CoFe/Cu/CoFe/NOL/Ta, were fabricated by dc magnetron sputtering. The magnetoresistance (MR), magnetization, and exchange bias have been studied as a function of IrMn composition and annealing temperature. It was ... [J. Appl. Phys. 103, 093908 (2008)] published Wed May 7, 2008.

Magnetocontrollable photonic crystals based on colloidal ferrofluids

C. Z. Fan, G. Wang, and J. P. Huang
We theoretically exploit a class of one-dimensional double-layer photonic crystals based on colloidal ferrofluids, which are made of ferromagnetic nanoparticles suspended in a carrier liquid. Depending on the magnetic-field-induced anisotropic property of the ferrofluid, precise controllability of t ... [J. Appl. Phys. 103, 094107 (2008)] published Wed May 7, 2008.

Structural and dielectric characterizations of relaxor/ferroelectric superlattice films Pb(Sc[sub 1/2]Nb[sub 1/2])O[sub 3]/PbTiO[sub 3] fabricated on a single-lattice scale

Shutaro Asanuma, Yoshiaki Uesu, Charlotte Malibert, and Jean-Michel Kiat
Relaxor/ferroelectric superlattice (SL) films Pb(ScNb)O(PSN)/PbTiO(PT) with nine different PT concentrations x are fabricated by a pulsed laser deposition method, which keeps the total film thickness at 100 nm. The structure of the SL films is examined by out-of-plane and in-plane x-ray diffractions ... [J. Appl. Phys. 103, 094106 (2008)] published Wed May 7, 2008.

On the impact testing of cyclotrimethylene trinitramine crystals with different internal qualities

R. H. B. Bouma, A. G. Boluijt, H. J. Verbeek, and A. E. D. M. van der Heijden
Impact testing of various cyclotrimethylene trinitramine (RDX) samples has been carried out with the Ballistic Impact Chamber (BIC). Numerical simulations have been performed to guide its experimental design and explain the phenomena that are observed in the measured pressure evolution. The experime ... [J. Appl. Phys. 103, 093517 (2008)] published Wed May 7, 2008.

Direct observation of domain wall structures in curved permalloy wires containing an antinotch

C. W. Sandweg, N. Wiese, D. McGrouther, S. J. Hermsdoerfer, H. Schultheiss et al.
The formation and field response of head-to-head domain walls in curved permalloy wires, fabricated to contain a single antinotch, have been investigated using Lorentz microscopy. High spatial resolution maps of the vector induction distribution in domain walls close to the antinotch have been deriv ... [J. Appl. Phys. 103, 093906 (2008)] published Wed May 7, 2008.

Intense electron beam generation in a high power cylindrical diode with a bipolar pulse

Amitava Roy, R. Menon, S. Mitra, D. D. P. Kumar, Senthil Kumar et al.
Our previously reported results demonstrated that an intense gigawatt relativistic electron beam can be generated in a cylindrical diode in the presence of prepulse. This article reports intense electron beam generation in a cylindrical electron beam diode when subjected to a high voltage bipolar pu ... [J. Appl. Phys. 103, 096104 (2008)] published Wed May 7, 2008.

Electrical characteristics of single-component ambipolar organic field-effect transistors and effects of air exposure on them

Tomo Sakanoue, Masayuki Yahiro, Chihaya Adachi, Kazuo Takimiya, and Akio Toshimitsu
We investigated the electrical characteristics of single-component ambipolar organic field-effect transistors (OFETs) by controlling the device structure and preparation and the measurement conditions. Six organic semiconductor materials (copper-phthalocyanine, tris-(8-hydroxyquinoline)aluminum (Alq ... [J. Appl. Phys. 103, 094509 (2008)] published Wed May 7, 2008.

Annealing-induced transition from a (311)A-oriented Ga[sub 0.98]Mn[sub 0.02]As alloy to a GaMnAs/MnAs hybrid structure studied by angle-dependent magnetotransport

M. T. Elm, P. J. Klar, W. Heimbrodt, U. Wurstbauer, M. Reinwald et al.
The angle-dependent behavior of the magneto-resistance of a series of low-temperature molecular beam epitaxy grown GaMnAs samples on (311)A-GaAs-substrates is studied. The samples are annealed at different temperatures in a range from 300 degrees C to 500 degrees C, which leads to a redistribution ... [J. Appl. Phys. 103, 093710 (2008)] published Wed May 7, 2008.

Ductile to brittle transition in dynamic fracture of brittle bulk metallic glass

G. Wang, Y. N. Han, X. H. Xu, F. J. Ke, B. S. Han et al.
We report an unusual transition from a locally ductile to a pure brittle fracture in the dynamic fracture of brittle MgCuGd bulk metallic glass. The fractographic evolution from a dimple structure to a periodic corrugation pattern and then to the mirror zone along the crack propagation direction dur ... [J. Appl. Phys. 103, 093520 (2008)] published Wed May 7, 2008.

Current-voltage characteristics of a graphene-nanoribbon field-effect transistor

V. Ryzhii, M. Ryzhii, A. Satou, and T. Otsuji
We present an analytical device model for a field-effect transistor based on a heterostructure, which consists of an array of nanoribbons clad between the highly conducting substrate (the back-gate) and the top gate controlling the source-drain current. The equations of the model of a grapheme-nanor ... [J. Appl. Phys. 103, 094510 (2008)] published Wed May 7, 2008.

Electro-thermal tuning in a negative dielectric cholesteric liquid crystal material

Lalgudi V. Natarajan, Jeremy M. Wofford, Vincent P. Tondiglia, Richard L. Sutherland, Hilmar Koerner et al.
The thermal and electrical tunability of a cholesteric liquid crystal containing a negative dielectric anisotropy liquid crystal in a planar alignment was studied. The physical, optical, and electro-optical characteristics of mixtures containing different ratios of chiral dopant S811 and the negativ ... [J. Appl. Phys. 103, 093107 (2008)] published Wed May 7, 2008.

Ga kinetics in plasma-assisted molecular-beam epitaxy of GaN(11[overline 2]2): Effect on the structural and optical properties

L. Lahourcade, J. Renard, B. Gayral, E. Monroy, M. P. Chauvat et al.
GaN directly deposited on m-sapphire by plasma-assisted molecular-beam epitaxy settles into two main crystalline orientation domains: GaN(11[overline 2]2) and GaN{10[overline 1]3}. The dominant phase is GaN(11[overline 2]2) with <11[overline 2][overline 3]>|| and <1[overline 1]00>||<11[overline 2]0> ... [J. Appl. Phys. 103, 093514 (2008)] published Tue May 6, 2008.

CoCr/Pt multilayers with adjustable perpendicular anisotropy

E. Th. Papaioannou, K. Lenz, M. Charilaou, P. Fumagalli, P. Poulopoulos et al.
CoCr/Pt multilayers are studied with respect to their structure, magnetic, and magneto-optical properties in an effort to produce novel films suitable for perpendicular magnetic recording. The multilayered structure and the face centered cubic stacking of the films are evidenced by x-ray diffraction ... [J. Appl. Phys. 103, 093905 (2008)] published Tue May 6, 2008.

Amorphous versus crystalline state for ultrathin Al[sub 2]O[sub 3] overgrowths on Al substrates

F. Reichel, L. P. H. Jeurgens, G. Richter, and E. J. Mittemeijer
The thermodynamic and kinetic background of the stability of ultrathin (<3 nm) amorphous AlO overgrowths on Al{111}, Al{100}, and Al{110} substrates was investigated by thermal oxidation of the bare substrates in pure oxygen gas for oxidation times up to 6000 s in the temperature range of T=350650 ... [J. Appl. Phys. 103, 093515 (2008)] published Tue May 6, 2008.

Dielectric relaxation in carbon black-epoxy composite materials

M. E. Achour, C. Brosseau, and F. Carmona
Filled polymers have been a fertile area for modeling studies of microwave dynamics, percolation, and elasticity network formation to mention but a few. To better understand the basic concepts relevant to wave transport in filled polymers, an experimental validation is paramount for theories that pr ... [J. Appl. Phys. 103, 094103 (2008)] published Tue May 6, 2008.

Improved gate oxide integrity of strained Si n-channel metal oxide silicon field effect transistors using thin virtual substrates

L. Yan, S. H. Olsen, E. Escobedo-Cousin, and A. G. O'Neill
This work presents a detailed study of ultrathin gate oxide integrity in strained Si metal oxide silicon field effect transistors (MOSFETs) fabricated on thin virtual substrates aimed at reducing device self-heating. The gate oxide quality and reliability of the devices are compared to those of simu ... [J. Appl. Phys. 103, 094508 (2008)] published Tue May 6, 2008.

Photocurrent spectroscopy of low-k dielectric materials: Barrier heights and trap densities

J. M. Atkin, D. Song, T. M. Shaw, E. Cartier, R. B. Laibowitz et al.
Measurements of photoinduced current have been performed on thin films of porous low-k dielectric materials comprised of carbon-doped oxides. The dielectric films were deposited on silicon surfaces and prepared with a thin gold counterelectrode. From the spectral dependence of the photoinduced curre ... [J. Appl. Phys. 103, 094104 (2008)] published Tue May 6, 2008.

Single-crystalline transparent and conductive oxide films with the perovskite structure: Sb-doped SrSnO[sub 3]

Q. Z. Liu, H. F. Wang, F. Chen, and Wenbin Wu
Perovskite-type transparent and conductive oxide films, Sb-doped SrSnO (SSSO), were grown on SrTiO(001) substrates by the pulsed laser deposition method. It is revealed that the films can be grown at relatively lower temperatures and show high single crystallinity with a cubic perovskite structure w ... [J. Appl. Phys. 103, 093709 (2008)] published Tue May 6, 2008.

Single-pulse excimer laser nanostructuring of silicon: A heat transfer problem and surface morphology

Julia Eizenkop, Ivan Avrutsky, Daniel G. Georgiev, and Vipin Chaudchary
We present computer modeling along with experimental data on the formation of sharp conical tips on silicon-based three-layer structures that consist of a single-crystal Si layer on a 1 [mu]m layer of silica on a bulk Si substrate. The upper Si layers with thicknesses in the range of 0.84.1 [mu]m ... [J. Appl. Phys. 103, 094311 (2008)] published Tue May 6, 2008.

Formation mechanism of Ohmic contacts on AlGaN/GaN heterostructure: Electrical and microstructural characterizations

Liang Wang, Fitih M. Mohammed, and Ilesanmi Adesida
The electrical characteristics and interfacial reactions of Ti/Al/Mo/Au metallization on AlGaN/GaN heterostructures at various annealing temperatures ranging from 400 to 950 degrees C have been investigated in an effort to elucidate the Ohmic contact formation mechanism. A transition from Schott ... [J. Appl. Phys. 103, 093516 (2008)] published Tue May 6, 2008.

Staebler--Wronski-like formation of defects at the amorphous-silicon--crystalline silicon interface during illumination

Heiko Plagwitz, Barbara Terheiden, and Rolf Brendel
The effective surface recombination velocity of amorphous-silicon-coated crystalline silicon wafers is measured after illumination for various durations to investigate the stability of the surface passivation. We develop a defect model to determine the densities of dangling bond states at the a-Si:H ... [J. Appl. Phys. 103, 094506 (2008)] published Tue May 6, 2008.

N-type carbon nanotube by alkaline-earth metal Sr doping

Byung Hoon Kim, Tae Hoi Park, Seung Jae Baek, Dong Su Lee, Seung Joo Park et al.
Alkaline-earth metal, Sr, was doped on multiwalled carbon nanotubes (MWNTs) by vapor phase reaction method. The tunneling electron microscopy, energy dispersive x ray, and Raman spectroscopy were studied for verifying the Sr doping on MWNT. The temperature-dependent resistivity [rho(T)] and thermoel ... [J. Appl. Phys. 103, 096103 (2008)] published Tue May 6, 2008.

The nonlinear dynamics of tapping mode atomic force microscopy with capillary force interactions

N. Hashemi, H. Dankowicz, and M. R. Paul
We study the nonlinear dynamics of a tapping mode atomic force microscope with tip-surface interactions that include attractive, repulsive, and capillary force contributions using numerical techniques tailored for hybrid or discontinuous dynamical systems that include forward-time simulation with ev ... [J. Appl. Phys. 103, 093512 (2008)] published Tue May 6, 2008.

Very high current density package level electromigration test for copper interconnects

Arijit Roy and Cher Ming Tan
In this paper, we present quantitative analyses of the impact of Joule heating on the package level electromigration (EM) test of copper dual damascene (DD) interconnects with linewidths of 0.28 and 0.7 [mu]m. A total of 120 samples are tested with a maximum current density of 8 MA/cm. It is found ... [J. Appl. Phys. 103, 093707 (2008)] published Tue May 6, 2008.

Laser-driven shock wave stability in Al through Au and determination of the TPa hugoniot point in Au

Hua Shu, Si-zu Fu, Xiu-guang Huang, Min-xun Ma, Jiang Wu et al.
High-quality shock waves were produced using the ninth laser beam (converted to 2omega) of Shenguang-II laser facility and the beam smoothing technology of a lens array. The spatial uniformity of the shock wave was estimated by measurements of the self-emission from the target rear surface. An AlAu ... [J. Appl. Phys. 103, 093304 (2008)] published Tue May 6, 2008.

Magnetism of the fcc Rh and Pd nanoparticles

Yoon Tae Jeon and Gang Ho Lee
We produced the fcc Rh and Pd nanoparticles with average particle diameters of 3 and 4 nm, respectively, in solution. We observed hysteretic behaviors in M-H curves and estimated lower bound magnetic moments of 4.8 x 10 and (3.8 x 10)[mu]/atom from unsaturated M-H curves at an applied field of 5 T a ... [J. Appl. Phys. 103, 094313 (2008)] published Tue May 6, 2008.

Synthesis and characterization of composite MgFe[sub 2]O[sub 4]--BaTiO[sub 3] multiferroic system

S. Y. Tan, S. R. Shannigrahi, S. H. Tan, and F. E. H. Tay
Multiferroic ceramics with the general formula (x)MgFeO(1x)BaTiO (x=0.4, 0.5, and 0.6) were synthesized by solid-state sintering process. From the x-ray diffraction analysis, it was observed that almost no chemical reaction occurs between the ferrite and the ferroelectric materials used to form the ... [J. Appl. Phys. 103, 094105 (2008)] published Tue May 6, 2008.