Journal of Applied Physics: All Topics

Intense 1.54 [mu]m fluorescence of Er/Yb codoped phosphate glass and the three-photon phenomenon of near infrared upconversion luminescence

Lanjun Luo, Feng Song, Xiaochen Yu, Wentao Wang, Chengguo Ming et al.
Transparent POCaONaO glasses codoped with Er and Yb ions were fabricated by high-temperature melting technique. Strong near infrared and visible upconversion luminescence were observed under 975 nm laser diode excitation, and the luminescence processes were explained in details. For 1.54 [mu]m band ... [J. Appl. Phys. 107, 033110 (2010)] published Tue Feb 9, 2010.

High-pressure behavior of beta-GaO nanocrystals

H. Wang, Y. He, W. Chen, Y. W. Zeng, K. Stahl et al.
Freestanding nanocrystalline beta-GaO particles with an average grain size of 14 nm prepared by chemical method was investigated by angle-dispersive synchrotron x-ray diffraction in diamond-anvil cell up to 64.9 GPa at ambient temperature. The evolution of x-ray diffraction patterns indicated that n ... [J. Appl. Phys. 107, 033520 (2010)] published Tue Feb 9, 2010.

Continuously tunable, phase-locked, continuous-wave terahertz generator based on photomixing of two continuous-wave lasers locked to two independent optical combs

Takeshi Yasui, Hisanari Takahashi, Yutaka Iwamoto, Hajime Inaba, and Kaoru Minoshima
A continuously tunable, phase-locked, single-frequency, continuous-wave (cw) terahertz generator has been demonstrated around 120 GHz, corresponding to the spectral bandwidth of the F-band unitraveling-carrier photodiode (UTC-PD) used as a photomixer in this study. This cw-terahertz generator is bas ... [J. Appl. Phys. 107, 033111 (2010)] published Tue Feb 9, 2010.

Tailoring absorption and emission of light in dielectric polymer nanofluids of reinforced poly(vinylidene fluoride) with silver nanoparticles

A. D. Phule, S. Ram, and A. K. Tyagi
Polymer nanofluids of poly(vinylidene fluoride) (PVF) containing 05 wt % Ag nanoparticles (Ag NPs) are synthesized via a simple in situ caloric Ag-->Ag reaction in liquid N,N-dimethyl formamide by sonication in hot conditions. An upright dielectric field on formation of a percolation network over th ... [J. Appl. Phys. 107, 034316 (2010)] published Tue Feb 9, 2010.

Optical generation of surface acoustic waves guided at the linear boundary between two thin films

A. A. Maznev, Timothy A. Kelf, Motonobu Tomoda, Osamu Matsuda, and Oliver B. Wright
Laser-induced transient grating measurements and ultrafast optical pump-probe imaging of surface acoustic waves near a linear boundary between copper and silica films on a silicon substrate indicate the presence of a boundary-localized mode with a phase velocity slightly below the Rayleigh wave velo ... [J. Appl. Phys. 107, 033521 (2010)] published Tue Feb 9, 2010.

Local density of electromagnetic states within a nanometric gap formed between two thin films supporting surface phonon polaritons

Mathieu Francoeur, M. Pinar Menguc, and Rodolphe Vaillon
We present a detailed physical analysis of the near-field thermal radiation spectrum emitted by a silicon carbide (SiC) film when another nonemitting SiC layer is brought in close proximity. This is accomplished via the calculation of the local density of electromagnetic states (LDOS) within the gap ... [J. Appl. Phys. 107, 034313 (2010)] published Tue Feb 9, 2010.

Thermal stability of microstructural and optical modifications induced in sapphire by ultrafast laser filamentation

A. Benayas, D. Jaque, Ben McMillen, and K. P. Chen
We report on the thermal stability of both structural and optical micromodifications created by ultrafast laser written filaments in sapphire crystals. By using the Cr traces as optical probes, we have concluded that the filaments are constituted by both reversible and nonreversible defects with ver ... [J. Appl. Phys. 107, 033522 (2010)] published Tue Feb 9, 2010.

Structure formation and very low thermal conductivity in Pb:Te:Ag:Se mixtures

Fivos R. Drymiotis, Tyler B. Drye, Yisha Wang, Jian He, Daniel Rhodes et al.
We have observed that reacting Pb:Te:Ag:Se in a 1:1:1.9:1 molar ratio gives rise to what appears to be a predominantly single-phase alloy, which crystallizes in the PbSe cF8 fcc structure. However, further investigation of the structure using energy dispersive x-ray analysis reveals the presence of ... [J. Appl. Phys. 107, 033519 (2010)] published Tue Feb 9, 2010.

Numerical investigation of flow-through immunoassay in a microchannel

A Sinha, R Ganguly, and I K. Puri
Immunomagnetic separation (IMS) is a method to isolate biomaterials from a host fluid in which specifically selected antibodies attached to magnetic particles bind with their corresponding antigens on the surface of the target biological entities. A magnet separates these entities from the fluid thr ... [J. Appl. Phys. 107, 034907 (2010)] published Tue Feb 9, 2010.

Electronic structure and magnetism of the diluted magnetic semiconductor Fe-doped ZnO nanoparticles

T. Kataoka, M. Kobayashi, Y. Sakamoto, G. S. Song, A. Fujimori et al.
We have studied the electronic structure of Fe-doped ZnO nanoparticles, which have been reported to show ferromagnetism at room temperature, by x-ray photoemission spectroscopy, resonant photoemission spectroscopy, x-ray absorption spectroscopy, and x-ray magnetic circular dichroism (XMCD). From the ... [J. Appl. Phys. 107, 033718 (2010)] published Tue Feb 9, 2010.

Effect of liquid environment on laser-induced backside wet etching of fused silica

Taehwa Lee, Deoksuk Jang, Daehwan Ahn, and Dongsik Kim
In laser-induced backside wet etching (LIBWE), the liquid absorbent indirectly heats the transparent material, causing explosive phase change and cavitation. Accordingly, the hydrodynamics of the absorbing liquid, including the size of the liquid chamber, is strongly related to the ablation process. ... [J. Appl. Phys. 107, 033112 (2010)] published Tue Feb 9, 2010.

Simulation of laser-induced backside wet etching of fused silica with hydrocarbon liquids

Klaus Zimmer, Martin Ehrhardt, and Rico Bohme
The mechanism of laser-induced backside wet etching (LIBWE) is important for the optimization of application processes but is still ambiguous. Extremely high surface absorption coefficients of more than 40 x 10 cm at lambda=248 nm that decay exponentially within less than 25 nm were measured for L ... [J. Appl. Phys. 107, 034908 (2010)] published Tue Feb 9, 2010.

Cluster-glass-like state and exchange bias effect in spontaneously phase separated, PrSrCoO

M. Patra, S. Majumdar, and S. Giri
dc magnetization and ac susceptibility measurements were carried out in a polycrystalline compound with composition PrSrCoO. Low-field dc magnetization and frequency-dependent ac susceptibility results suggest a cluster-glass-like transition at 165 K. When the sample was cooled in a static magnetic ... [J. Appl. Phys. 107, 033912 (2010)] published Tue Feb 9, 2010.

Interaction of vacuum ultraviolet excimer laser radiation with fused silica: II. Neutral atom and molecule emission

Sharon R. George, S. C. Langford, and J. T. Dickinson
We report mass-resolved time-of-flight measurements of neutral Si, O, and SiO from ultraviolet-grade fused silica during pulsed 157-nm irradiation at fluences well below the threshold for optical breakdown. Although the emission intensities are strongly affected by thermal treatments that affect the ... [J. Appl. Phys. 107, 033108 (2010)] published Tue Feb 9, 2010.

Ultraviolet photorefraction at 325 nm in doped lithium niobate crystals

Feifei Xin, Guoquan Zhang, Fang Bo, Haifeng Sun, Yongfa Kong et al.
We studied the photorefractive effect of lithium niobate (LiNbO) doped with Mg, Zn, In, Hf, or codoped with Mg and Fe at an ultraviolet (UV) wavelength down to 325 nm. It is found that the UV photorefraction of LiNbO doped with Mg, Zn, In, or Hf was enhanced significantly as compared to that of the ... [J. Appl. Phys. 107, 033113 (2010)] published Tue Feb 9, 2010.

Interaction of vacuum ultraviolet excimer laser radiation with fused silica. I. Positive ion emission

Sharon R. George, John A. Leraas, S. C. Langford, and J. T. Dickinson
We report time- and mass-resolved measurements of Si and O emission from ultraviolet-grade fused silica during exposure to pulsed 157 nm excimer laser radiation at fluences below the threshold for optical breakdown. The emission intensities are increased by treatments that increase the density of su ... [J. Appl. Phys. 107, 033107 (2010)] published Tue Feb 9, 2010.

Influence of multiple magnetic phases on the extrinsic damping of FeCoSiO soft magnetic films

Bailin Liu, Yi Yang, Dongming Tang, Jiangwei Chen, Huaixian Lu et al.
In order to investigate the high-frequency damping properties of the ferromagnetic film for the electromagnetic shielding applications, a series of (FeCo)/(Fe)/(SiO) nanogranular films with various volume fractions (x) were fabricated by alternate triple-target magnetron sputtering. The (FeCo)/Fe/(S ... [J. Appl. Phys. 107, 033911 (2010)] published Tue Feb 9, 2010.

Functionalized single wall carbon nanotube sensor in a perturbed microwave resonant cavity based toxin/pollutant gas pressure sensor

S. B. Tooski
The Vlasov and Maxwell's equations are established and solved numerically to describe the effects of toxin/pollutant gas pressure and functionalized single wall carbon nanotube (SWCNT) sensor in a perturbed microwave resonant cavity. The dependence of the absorption coefficient on incident frequency ... [J. Appl. Phys. 107, 034315 (2010)] published Tue Feb 9, 2010.

Semiconducting SnO nanobelts: Growth and electronic structure

O. M. Berengue, R. A. Simon, A. J. Chiquito, C. J. Dalmaschio, E. R. Leite et al.
The study of structures based on nonstoichiometric SnO compounds, besides experimentally observed, is a challenging task taking into account their instabilities. In this paper, we report on single crystal SnO nanobelts, which were successfully grown by a carbothermal evaporation process of SnO powde ... [J. Appl. Phys. 107, 033717 (2010)] published Tue Feb 9, 2010.

Current noise correlations in double quantum dots asymmetrically coupled to external leads

Hai-Feng Lu, Jun-Rui Zhang, Tao Wu, Xiao-Tao Zu, and Huai-Wu Zhang
We investigate the current noise autocorrelations and cross correlations through two interacting quantum dots coupled to four external leads. The results indicate sign reversal of the cross correlation in different tunneling regions, respect to competing or supporting processes. By adjusting the dot ... [J. Appl. Phys. 107, 034314 (2010)] published Tue Feb 9, 2010.

Interaction of vacuum ultraviolet excimer laser radiation with fused silica. III. Negative ion formation

Sharon R. George, S. C. Langford, and J. T. Dickinson
We report mass- and time-resolved measurements of negative ions produced by exposing fused silica to 157 nm radiation at fluences below the threshold for optical breakdown. The principal observed negative ions are O, Si, and SiO, in order of decreasing intensity. The peak in the negative ion time-of ... [J. Appl. Phys. 107, 033109 (2010)] published Tue Feb 9, 2010.

Microwave permeability of flake-shaped FeCuNbSiB particle composite with rotational orientation

Weifeng Yang, Liang Qiao, Jianqiang Wei, Zhaoqi Zhang, Tao Wang et al.
Flake-shaped FeCuNbSiB particles were fabricated by ball milling the annealed ribbons. The composites of flake particles/paraffin wax were prepared with and without rotational orientation in an applied magnetic field. The complex permeability of the composites was measured in the frequency range of ... [J. Appl. Phys. 107, 033913 (2010)] published Tue Feb 9, 2010.

Phase-dependent thermal conductivity of GeSbTe and N:GeSbTe for phase change memory applications

Sangwoo Shin, Hyung Keun Kim, Jiwoon Song, Doo Jin Choi, and Hyung Hee Cho
We report the thermal conductivities of GeSbTe and nitrogen-doped GeSbTe thin films at temperatures ranging from 300 to 520 K using the 3omega method. Thermal conductivity of GeSbTe increases abruptly during the transition from the amorphous to crystalline phase. Nitrogen doping effectively suppress ... [J. Appl. Phys. 107, 033518 (2010)] published Tue Feb 9, 2010.

Writer pole remanence of a tapered main pole head

Maki Maeda, Hiroki Kobayashi, Junzo Toda, Yuichi Sato, and Shin Eguchi
We used a micromagnetic model to study the head remanence of a perpendicular tapered main pole head. To reduce the head pole tip remanence, a single magnetic domain structure forming a vortex state from the pole tip to the tapered region is preferred. A tapered main pole structure with a trailing ga ... [J. Appl. Phys. 107, 033910 (2010)] published Tue Feb 9, 2010.

Optical transition dynamics in ZnO/ZnMgO multiple quantum well structures with different well widths grown on ZnO substrates

Song-Mei Li, Bong-Joon Kwon, Ho-Sang Kwack, Li-Hua Jin, Yong-Hoon Cho et al.
We report the optical properties of ZnO/ZnMgO multiple quantum well (MQW) structures with different well widths grown on ZnO substrates by molecular beam epitaxy. Photoluminescence (PL) spectra show MQW emissions at 3.387 and 3.369 eV for the ZnO/ZnMgO MQW samples with well widths of 2 and 5 nm, res ... [J. Appl. Phys. 107, 033513 (2010)] published Mon Feb 8, 2010.

The dual role of nitrogen as alloying and confining element in GaAs-based dilute nitride semiconductors

H. E. Porteanu, O. Loginenko, and F. Koch
We examine transport and relaxation dynamics of optically excited electrons in GaAs-based heterostructure layers, involving dilute nitrides in percent-level concentration range. Such heterostructures contain materials with very different mobilities. Drift instead of Hall mobility is determined using ... [J. Appl. Phys. 107, 033714 (2010)] published Mon Feb 8, 2010.

Hydrogen-doped InO transparent conducting oxide films prepared by solid-phase crystallization method

Takashi Koida, Michio Kondo, Koichi Tsutsumi, Akio Sakaguchi, Michio Suzuki et al.
We have characterized amorphous to crystalline transformation of hydrogen (H)-doped InO (InO:H) films by transmission electron microscopy, thermal desorption spectroscopy, spectroscopic ellipsometry, and Hall measurements. The InO:H films that show a mixed-phase structure embedded with small density ... [J. Appl. Phys. 107, 033514 (2010)] published Mon Feb 8, 2010.

Jump properties of the tip magnetic field of a notch in a melt-processes yttrium-barium-copper-oxide bulk

Xing-Yi Zhang, Jun Zhou, and You-He Zhou
We report on a direct measurement of the magnetic field properties at the tip of a notch in melt-processed YBaCuO bulks. In the case of the fixed notch angle, when the notch length increases and reaches a critical value, the tip magnetic field will increase and exceed the initial value of the sample ... [J. Appl. Phys. 107, 036102 (2010)] published Mon Feb 8, 2010.

Electronic structure, phonons, and thermal properties of ScN, ZrN, and HfN: A first-principles study

Bivas Saha, Jagaran Acharya, Timothy D. Sands, and Umesh V. Waghmare
With a motivation to understand microscopic aspects of ScN, ZrN, and HfN relevant to the thermoelectric properties of nitride metal/semiconductor superlattices, we determine their electronic structure, vibrational spectra and thermal properties using first-principles calculations based on density fu ... [J. Appl. Phys. 107, 033715 (2010)] published Mon Feb 8, 2010.

Theoretical and experimental investigation of optically driven nanoelectromechanical oscillators

B. Ilic, S. Krylov, and H. G. Craighead
The actuation of biologically functional micro- and nanomechanical structures using optical excitation is an emerging arena of research that couples the fields of optics, fluidics, electronics, and mechanics with potential for generating novel chemical and biological sensors. In our work, we fabrica ... [J. Appl. Phys. 107, 034311 (2010)] published Mon Feb 8, 2010.

Nanocrystalline diamond as an electronic material: An impedance spectroscopic and Hall effect measurement study

Mose Bevilacqua, Niall Tumilty, Chiranjib Mitra, Haitao Ye, Tatayana Feygelson et al.
Nanocrystalline diamond (NCD) has been grown using a nanodiamond seeding technique, leading to a dense form of this material, with grain sizes around 100 nm. The electrical properties of both intrinsic and lightly boron-doped NCD have been investigated using impedance spectroscopy and Hall effect me ... [J. Appl. Phys. 107, 033716 (2010)] published Mon Feb 8, 2010.

Controllable spin-polarized electrical transport in wide-band-gap oxide ferromagnetic semiconductors

Y. F. Tian, Shi-shen Yan, M. W. Zhao, Y. Y. Dai, Y. P. Zhang et al.
A family of wide-band-gap ternary oxide ferromagnetic semiconductor films with high transition metal concentration was prepared. The resistivity of these films can be changed up to four orders of magnitude by varying the composition or the concentration of the oxygen vacancies. Moreover, all these f ... [J. Appl. Phys. 107, 033713 (2010)] published Mon Feb 8, 2010.

Enhancement of Co substitution induced by Eu codoping in ZnO-based diluted magnetic semiconducting thin films

P. Photongkam, Y. B. Zhang, M. H. N. Assadi, S. Li, D. Yu et al.
To avoid the occurrence of doped magnetic ion clustering is a challenge in fabrication of diluted magnetic semiconductors (DMSs). In this work, we report the intrinsic ferromagnetic behavior in Co-doped ZnO DMSs induced by Eu codoping. Both structural parameters and magnetic properties demonstrate t ... [J. Appl. Phys. 107, 033909 (2010)] published Mon Feb 8, 2010.

Localized sagittal modes of variable transverse and longitudinal components in one-dimensional phononic crystals

L. Castro-Arce, B. Manzanares-Martinez, and F. Ramos-Mendieta
In this paper, we study the polarization states of the localized sagittal modes in a solid/solid one-dimensional phononic crystal with a defect layer. We have found that the well defined polarization of these modes, either transverse or longitudinal, for propagation in the direction of periodicity i ... [J. Appl. Phys. 107, 033515 (2010)] published Mon Feb 8, 2010.

Strain engineered segregation regimes for the fabrication of thin SiGe layers with abrupt n-type doping

I. Berbezier, J. P. Ayoub, A. Ronda, M. Oehme, K. Lyutovich et al.
We implement a low temperature (LT) growth technique for achieving abrupt n-type doping profiles in order to match the vertical scaling of modulation doped field effect transistor fully depleted structures. We use strain engineering of Ge rich SiGe layers at LTs to suppress dopant segregation and to ... [J. Appl. Phys. 107, 034309 (2010)] published Mon Feb 8, 2010.

Self-masking controlled by metallic seed layer during glass dry-etching for optically scattering surfaces

E. Hein, D. Fox, and H. Fouckhardt
During reactive ion etching in a high density Ar/CF plasma, nonvolatile halogen compounds are generated on the glass surface and act as statistically distributed micromasks. As a consequence surface roughness occurs, which can be used as additional surface functionality in certain classes of applica ... [J. Appl. Phys. 107, 033301 (2010)] published Mon Feb 8, 2010.

Bond-order potential for point and extended defect simulations in tungsten

T. Ahlgren, K. Heinola, N. Juslin, and A. Kuronen
A reactive interatomic bond-order potential for bcc tungsten is presented. Special attention in the potential development was given for obtaining accurate formation and migration energies for point defects, making the potential useful in atomic scale simulations of point and extended defects. The po ... [J. Appl. Phys. 107, 033516 (2010)] published Mon Feb 8, 2010.

Neodymium doping in UV-IR transparent ferroelectric BaMgF

E. G. Villora, P. Molina, S. Alvarez, J. V. Garcia-Santizo, M. O. Ramirez et al.
The incorporation of Nd in the ferroelectric fluoride BaMgF crystal is investigated for its potential application as self-frequency-converter solid state laser. Low temperature high-resolution optical spectroscopy shows that Nd is located at two well distinguished sites referred as A and B. The whol ... [J. Appl. Phys. 107, 033106 (2010)] published Mon Feb 8, 2010.

Temperature dependence of electric and dielectric behaviors of Ni/polyvinylidene fluoride composites

Hai-Ping Xu, Zhi-Min Dang, Nai-Ci Bing, Yi-Hua Wu, and Dan-Dan Yang
Composites of polyvinylidene fluoride (PVDF) filled with metallic particles of nickel (Ni) were prepared via a blending and hot-molding technique. Rescaled temperature dependence of electric and dielectric behaviors of Ni/PVDF composites were studied at wide content ranges. Results show that there i ... [J. Appl. Phys. 107, 034105 (2010)] published Mon Feb 8, 2010.

Scanning tunneling microscopic analysis of Cu(In,Ga)Se epitaxial layers

Marie A. Mayer, Laura B. Ruppalt, Damon Hebert, Joseph Lyding, and Angus A. Rockett
Scanning tunneling microscopy (STM) measurements have been made on single-crystal epitaxial layers of CuInSe grown on GaAs substrates. Results were obtained for as-grown, air-exposed, and cleaned surfaces; in situ cleaved surfaces; surfaces sputtered and annealed in the STM system; and samples prepa ... [J. Appl. Phys. 107, 034906 (2010)] published Mon Feb 8, 2010.

Ultrafast studies of carrier and magnetization dynamics in GaMnAs

J. P. Zahn, A. Gamouras, S. March, X. Liu, J. K. Furdyna et al.
We have investigated the carrier and magnetization dynamics in a GaMnAs structure with perpendicular uniaxial anisotropy using time-resolved pump probe techniques. Experiments were performed over two orders of magnitude variation in pump fluence, revealing an ultrafast demagnetization response that ... [J. Appl. Phys. 107, 033908 (2010)] published Mon Feb 8, 2010.

First-principles study of alkali-atom doping in a series of zigzag and armchair carbon nanotubes

Y. W. Wen, H. J. Liu, X. J. Tan, L. Pan, and J. Shi
First-principles calculations are performed to study the Li doping in a series of carbon nanotubes with different diameters and chiralities. It is found that the LiLi interaction inside or outside zigzag tubes is repulsive but strongly screened. Moreover, small diameter zigzag tubes are energeticall ... [J. Appl. Phys. 107, 034312 (2010)] published Mon Feb 8, 2010.

Constitutive modeling of intrinsic silicon monocrystals in easy glide

J. Cochard, I. Yonenaga, S. Gouttebroze, M. M'Hamdi, and Z. L. Zhang
Constitutive modeling of silicon materials is currently restricted to the very early stage of deformation. Uniaxial tensile testing of monocrystals oriented for single glide is traditionally simulated by a scalar model relying on the so-called machine equation. The present work uses a crystal plasti ... [J. Appl. Phys. 107, 033512 (2010)] published Mon Feb 8, 2010.

Enhanced ultraviolet electroluminescence from ZnO nanowires in TiO/ZnO coaxial nanowires/poly(3,4-ethylenedioxythiophene)-poly(styrene-sulfonate) heterojunction

Chun-Yu Lee, Jen-Yi Wang, Yi Chou, MengYueh Liu, Wei-Fang Su et al.
The ultraviolet (UV) electroluminescence (EL) from the TiO/ZnO coaxial nanowires (NWs)/poly(3,4-ethylenedioxythiophene)-poly(styrene-sulfonate) inorganic/organic heterostructure devices is greatly enhanced and the defect emission is significantly suppressed compared with the uncoated ZnO NW device a ... [J. Appl. Phys. 107, 034310 (2010)] published Mon Feb 8, 2010.

Structural analysis of silicon carbon nitride films prepared by vapor transport-chemical vapor deposition

Y. Awad, M. A. El Khakani, M. Scarlete, C. Aktik, R. Smirani et al.
Amorphous silicon carbon nitride (a-SiCN:H) films were synthesized using vapor transport-chemical vapor deposition technique. Poly(dimethylsilane) was used as a single source for both Si and C. NH gas diluted in Ar is used as a source for nitrogen. The composition and bonding states are uniquely cha ... [J. Appl. Phys. 107, 033517 (2010)] published Mon Feb 8, 2010.

Fabrication of advanced La-incorporated Hf-silicate gate dielectrics using physical-vapor-deposition-based in situ method and its effective work function modulation of metal/high-k stacks

Hiroaki Arimura, Yudai Oku, Masayuki Saeki, Naomu Kitano, Takuji Hosoi et al.
Lanthanum (La) incorporation into Hf-silicate high-permittivity (high-k) gate dielectrics was conducted using a physical-vapor-deposition (PVD)-based in situ method. PVD-grown metal Hf, La, and HfLa alloys on base SiO oxides received in situ annealing to form high-quality HfLaSiO dielectrics, and su ... [J. Appl. Phys. 107, 034104 (2010)] published Mon Feb 8, 2010.

The challenge of unity wall plug efficiency: The effects of internal heating on the efficiency of light emitting diodes

Oskari Heikkila, Jani Oksanen, and Jukka Tulkki
We develop a self-consistent model to describe the internal heating of high power light emitting diodes (LEDs) and use this model to simulate the operation of GaAsAlGaAs double heterostructure LEDs. We account for the heating by nonradiative recombination processes in the simulations and solve self- ... [J. Appl. Phys. 107, 033105 (2010)] published Mon Feb 8, 2010.

Electrical properties of ZnO nanowire field effect transistors with varying high-k AlO dielectric thickness

Minhyeok Choe, Gunho Jo, Jongsun Maeng, Woong-Ki Hong, Minseok Jo et al.
We investigated the electronic properties of ZnO nanowire combined with the scaled high-k AlO dielectrics using metal-oxide-semiconductor and field effect transistor (FET) device structures. We found that AlO dielectric material can significantly reduce leakage currents when the applied voltage was ... [J. Appl. Phys. 107, 034504 (2010)] published Fri Feb 5, 2010.

Design considerations for surface plasmon resonance based detection of human blood group in near infrared

Anuj K. Sharma, Rajan Jha, and Himansu S. Pattanaik
Surface plasmon resonance based sensor for detection of different human blood groups in near infrared region is proposed. The plasmonic structure is based on fused silica or chalcogenide sulfide glass GeGaSbS, commonly known as 2S2G. Experimental results describing the wavelength-dependent refractiv ... [J. Appl. Phys. 107, 034701 (2010)] published Fri Feb 5, 2010.

Cloaking a metal object from an electromagnetic pulse: A comparison between various cloaking techniques

Pekka Alitalo, Henrik Kettunen, and Sergei Tretyakov
Electromagnetic cloaks are devices that can be used to reduce the total scattering cross section of various objects. An ideal cloak removes all scattering from an object and thus makes this object invisible to the electromagnetic fields that impinge on the object. However, ideal cloaking appears to ... [J. Appl. Phys. 107, 034905 (2010)] published Fri Feb 5, 2010.

Scaling consideration and compact model of electron scattering enhancement due to acoustic phonon modulation in an ultrafine free-standing cylindrical semiconductor nanowire

Junichi Hattori, Shigeyasu Uno, Kazuo Nakazato, and Nobuya Mori
We theoretically investigate the interaction between modulated acoustic phonons and electrons in a free-standing cylindrical semiconductor nanowire and calculate the electron mobility limited by modulated acoustic phonons in a [001]-oriented silicon nanowire (SiNW) at room temperature. The mobility ... [J. Appl. Phys. 107, 033712 (2010)] published Fri Feb 5, 2010.

Spectroscopic aspects of front transparent conductive films for a-Si thin film solar cells

Qi Hua Fan, Changyong Chen, Xianbo Liao, Xianbi Xiang, Xinmin Cao et al.
This work demonstrates a method to optimize the indium tin oxide (ITO) thin films as front transparent electrode to maximize the efficiency of substrate type amorphous silicon (a-Si) based thin film solar cells. It shows that the total light intensity absorbed by the a-Si layer can be predicted by c ... [J. Appl. Phys. 107, 034505 (2010)] published Fri Feb 5, 2010.

Influence of freely diffusing excitons on the photoluminescence spectrum of Si thick films with depth distribution of strain

Dong Wang, Haigui Yang, Tokuhide Kitamura, and Hiroshi Nakashima
We present an interpretation of photoluminescence (PL) for relatively thick Si films (200300 nm) with depth distribution of strain, in which freely diffusing excitons influence the PL signal that originates from layers with different strain conditions. Micro-PL was excited by a 325 nm laser at 8.5 K ... [J. Appl. Phys. 107, 033511 (2010)] published Fri Feb 5, 2010.

Griffiths phase and exchange bias in LaCaMnO (x=0.50, 0.67, and 0.75) nanoparticles

S. M. Zhou, S. Y. Zhao, Y. Q. Guo, J. Y. Zhao, and L. Shi
The magnetic properties of LaCaMnO (x=0.50, 0.67, and 0.75) nanoparticles have been systemically investigated in this work. It is found that although their bulk counterparts have different magnetic and charge ordered states, the nanoparticles show no long-range charge ordered transition but very sim ... [J. Appl. Phys. 107, 033906 (2010)] published Thu Feb 4, 2010.

The effect of impurities on spin-polarized Zeeman bound states in dilute magnetic semiconductor-superconductor hybrids

Shi-Hsin Lin, Tatiana G. Rappoport, Mona Berciu, and Boldizsar Janko
We investigate the effect of single and multiple impurities on the Zeeman-localized, spin-polarized bound states in dilute magnetic semiconductor hybrid system. Such bound states appear whenever a dilute magnetic semiconductor showing giant Zeeman effect is exposed to an external magnetic field show ... [J. Appl. Phys. 107, 034307 (2010)] published Thu Feb 4, 2010.

Magnetic cellular automata coplanar cross wire systems

Javier F. Pulecio and Sanjukta Bhanja
Quantum cellular automata has proposed an exclusive architecture where two coplanar perpendicular wires have the ability to intersect one another without signal degradation. The physical realization of cross wire architectures has yet to be implemented and researchers share concerns over the reliabi ... [J. Appl. Phys. 107, 034308 (2010)] published Thu Feb 4, 2010.

The jump phenomenon in the angular dependence of the off-aligned exchange bias

Yuhao Bai (白宇浩), Guohong Yun (云国宏), and Narsu Bai (白那日苏)
Based on the principle of minimal energy, the angular dependence of exchange bias has been investigated in detail with noncollinear easy axes of unidirectional and uniaxial anisotropies in the ferromagnetic/antiferromagnetic bilayers. The competition between unidirectional and uniaxial anisotropies ... [J. Appl. Phys. 107, 033905 (2010)] published Thu Feb 4, 2010.

Precessional dynamics of NiFe thin films for ultrahigh frequency integrated magnetics

Jeffrey F. Godsell, Santosh Kulkarni, Terence O'Donnell, and Saibal Roy
Future monolithic point of load switched mode power supplies will be expected to meet the energy requirements of miniaturized, high functionality electronic devices. Recently, NiFe has emerged as a potentially important material choice for use as a soft magnetic core material within high frequency i ... [J. Appl. Phys. 107, 033907 (2010)] published Thu Feb 4, 2010.

Phase retrieval tomography in the presence of noise

B. D. Arhatari, W. P. Gates, N. Eshtiaghi, and A. G. Peele
We describe the use of single-plane phase retrieval tomography using a laboratory-based x-ray source, under conditions where the retrieval is not formally valid, to present images of the internal structure of an Aerosil granule and a hydrated bentonite gel. The technique provides phase images for sa ... [J. Appl. Phys. 107, 034904 (2010)] published Thu Feb 4, 2010.

Temperature and excitation power dependent photoluminescence intensity of GaInN quantum wells with varying charge carrier wave function overlap

C. Netzel, V. Hoffmann, T. Wernicke, A. Knauer, M. Weyers et al.
For the realization and the improvement of GaN-based optoelectronic devices (light emitting diodes and laser diodes) emitting from the ultraviolet to the red wavelength range GaInN quantum well structures with high internal quantum efficiency are of great importance. To determine parameters which af ... [J. Appl. Phys. 107, 033510 (2010)] published Thu Feb 4, 2010.

Photoresponsive characteristics and hysteresis of soluble 6,13-bis(triisopropyl-silylethynyl)-pentacene-based organic thin film transistors with and without annealing

Mi Yeon Cho, Yoon Deok Han, Han Saem Kang, Kihyun Kim, Kyung Hwan Kim et al.
We report on the photoresponsive characteristics and hysteresis of soluble 6,13-bis(triisopropyl-silylethynyl; TIPS)-pentacene-based organic thin film transistors (OTFTs) with and without an annealing process. Under incident light, the hysteresis and memory effect increased for the annealed devices ... [J. Appl. Phys. 107, 033711 (2010)] published Wed Feb 3, 2010.

Plasmonic noise in silicon nanolayers

J. Pousset, J.-F. Millithaler, L. Reggiani, P. Ziade, G. Sabatini et al.
We report a microscopic investigation of the spectrum of voltage fluctuations in nanometric n-Si layers. Theory makes use of a Monte Carlo simulator self-consistently coupled with a two-dimensional Poisson solver. We consider layers of variable thickness W in the range of 2100 nm and variable lengt ... [J. Appl. Phys. 107, 033710 (2010)] published Wed Feb 3, 2010.

Acoustic impedance measurements of pulse tube refrigerators

Takashi Iwase, Tetsushi Biwa, and Taichi Yazaki
Complex acoustic impedance is determined in a prototype refrigerator that can mimic orifice-type, inertance-type, and double inlet-type pulse tube refrigerators from simultaneous measurements of pressure and velocity oscillations at the cold end. The impedance measurements revealed the means by whic ... [J. Appl. Phys. 107, 034903 (2010)] published Wed Feb 3, 2010.

Effect of dipole interaction on microwave assisted magnetization switching

S. Okamoto, N. Kikuchi, O. Kitakami, and M. Igarashi
Microwave assisted switching (MAS) of magnetization has attracted much attention as an alternative technique for future ultrahigh density magnetic recording. In this study, to elucidate the effect of magnetostatic interparticle interaction on MAS, we have calculated the switching behavior for a row ... [J. Appl. Phys. 107, 033904 (2010)] published Wed Feb 3, 2010.

Reactive dc magnetron sputtering of (GeOSiO) superlattices for Ge nanocrystal formation

M. Zschintzsch, N. M. Jeutter, J. von Borany, M. Krause, and A. Mucklich
The motivation of this work is the tailored growth of Ge nanocrystals for photovoltaic applications. The use of superlattices provides a reliable method to control the Ge nanocrystal size after phase separation. In this paper, we report on the deposition of (GeOSiO) superlattices via reactive dc mag ... [J. Appl. Phys. 107, 034306 (2010)] published Wed Feb 3, 2010.

Growth and characterization of In-polar and N-polar InAlN by metal organic chemical vapor deposition

David F. Brown, Stacia Keller, Thomas E. Mates, James S. Speck, Steven P. DenBaars et al.
InAlN layers, with 0.09<=x<=0.23, were grown on GaN on both the In-polar and N-polar orientations by metal organic chemical vapor deposition. The impact of growth conditions, including temperature and the group-III flow rates, on the surface morphology and indium mole fraction was investigated. In-p ... [J. Appl. Phys. 107, 033509 (2010)] published Wed Feb 3, 2010.

Compositional effects on the growth of Mg(M)O films

M. Saraiva, V. Georgieva, S. Mahieu, K. Van Aeken, A. Bogaerts et al.
The influence of the composition on the crystallographic properties of deposited Mg(M)O (with M=Al, Cr, Ti, Y, and Zr) films is studied. For a flexible control of the composition, dual reactive magnetron sputtering was used as deposition technique. Two different approaches to predict the composition ... [J. Appl. Phys. 107, 034902 (2010)] published Wed Feb 3, 2010.

Phase compatibility and thermoelectric properties of compounds in the SrCaCoO system

W. Wong-Ng, G. Liu, J. Martin, E. L. Thomas, N. Lowhorn et al.
Two low-dimensional cobaltite series in the SrCaCoO system have been investigated for their solid solution limit, structure, and compatibility phase relationships (850 degrees C in air). Thermoelectric properties have been measured for selected members of these solid solutions. In (Ca,Sr)CoO, which ... [J. Appl. Phys. 107, 033508 (2010)] published Wed Feb 3, 2010.

Enhanced high temperature thermoelectric characteristics of transition metals doped CaCoO by cold high-pressure fabrication

Yang Wang, Yu Sui, Xianjie Wang, Wenhui Su, and Xiaoyang Liu
A series of Fe, Mn, and Cu doped CaCoO samples, Ca(Co,M)O (M=Fe, Mn, and Cu), were fabricated by cold high-pressure compacting technique. Their thermoelectric properties were investigated from room temperature up to 1000 K. The cold high-pressure compacting method is advantageous to increasing densi ... [J. Appl. Phys. 107, 033708 (2010)] published Tue Feb 2, 2010.

Atomic structure of a Ni diffused Si (001) surface layer: Precursor to formation of NiSi at low temperature

Nobuyuki Ikarashi
The atomic structure in a Ni-diffused Si (001) surface layer was determined by using aberration-corrected scanning-transmission electron microscopy (STEM). The STEM investigation revealed three key findings. First, Ni atoms occupy the tetrahedral interstitial voids of a Si crystal at an occupancy fa ... [J. Appl. Phys. 107, 033505 (2010)] published Tue Feb 2, 2010.

Electronic and ionic contributions to the constant-volume specific heat of carbon tetrachloride shocked at pressures up to 23 GPa

Yukio Sano, Tomokazu Sano, and Shinichi Nagata
For carbon tetrachloride, a temperature Hugoniot at 723 GPa and a distribution of the constant-volume specific heat on the Hugoniot C(T) at 10573275 K are simultaneously estimated from the WalshChristian (WC) equation such that the Hugoniot fits well to the existing measured data. The estimated C(T) ... [J. Appl. Phys. 107, 033507 (2010)] published Tue Feb 2, 2010.

Long-ranged and high temperature ferromagnetism in (Mn,C)-codoped ZnO studied by first-principles calculations

Xue-ling Lin, Shi-shen Yan, Ming-wen Zhao, Shu-jun Hu, Xin-xin Yao et al.
We theoretically investigated the electronic structures and magnetic properties of (Mn,C)-codoped ZnO system based on the first-principles calculations within a GGA+U approach. We found that codoping C is a promising approach to enhance the ferromagnetic coupling between the nearest-neighboring Mn i ... [J. Appl. Phys. 107, 033903 (2010)] published Tue Feb 2, 2010.

Effects of illumination on the excess carrier dynamics and variations of the surface states in an AlGaN/GaN heterostructure

Yun-Chorng Chang
Light illumination was observed to be able to change the charge status of surface states in an AlGaN/GaN heterostructure and vary the conductivity of the two-dimensional electron gas channel. The effects of several parameters, including sample temperature, intensity of the ultraviolet (UV) light, wa ... [J. Appl. Phys. 107, 033706 (2010)] published Tue Feb 2, 2010.

Slit waveguide based terahertz near-field microscopy: Prospects and limitations

Hannes Merbold and Thomas Feurer
We experimentally and numerically investigate the transmission of single cycle terahertz pulses through subwavelength slit apertures featuring zero cutoff frequency and very low attenuation. Employing a polaritonic approach we demonstrate that wave forms transmitted through slit samples with slit wi ... [J. Appl. Phys. 107, 033504 (2010)] published Tue Feb 2, 2010.

Improved ferroelectric behavior in (110) oriented BiFeO thin films

Jiagang Wu and John Wang
Multiferroic BiFeO thin films were grown on LaNiO-buffered Pt/TiO/SiO/Si substrates by off-axis radio frequency magnetic sputtering, where (110) oriented texture was obtained. The LaNiO buffer layer promoted the growth of BiFeO film, resulting in a dense texture and columnar growth of BiFeO thin fil ... [J. Appl. Phys. 107, 034103 (2010)] published Tue Feb 2, 2010.

Drain current model for thin-film transistors with interface trap states

Hiroshi Tsuji, Yoshinari Kamakura, and Kenji Taniguchi
A surface-potential-based drain current model for thin-film transistors (TFTs) is presented. In this model, the influence of traps located at the gate-oxide/silicon interface is accounted for to reproduce the gradual increase in the subthreshold current. The model uses a single equation that include ... [J. Appl. Phys. 107, 034502 (2010)] published Tue Feb 2, 2010.

Substrate doping effects on Raman spectrum of epitaxial graphene on SiC

R. Yang, Q. S. Huang, X. L. Chen, G. Y. Zhang, and H.-J. Gao
In this paper, we reported a Raman scattering study of epitaxial graphene on different doped 6H-SiC (0001) substrates and investigated the substrate induced charge-transfer doping to the epitaxial graphene. We found that the charge carrier type and concentration of epitaxial graphene can be altered ... [J. Appl. Phys. 107, 034305 (2010)] published Tue Feb 2, 2010.

On eigenmodes, stiffness, and sensitivity of atomic force microscope cantilevers in air versus liquids

Daniel Kiracofe and Arvind Raman
The effect of hydrodynamic loading on the eigenmode shapes, modal stiffnesses, and optical lever sensitivities of atomic force microscope (AFM) microcantilevers is investigated by measuring the vibrations of such microcantilevers in air and water using a scanning laser Doppler vibrometer. It is foun ... [J. Appl. Phys. 107, 033506 (2010)] published Tue Feb 2, 2010.

Phase transitions in Co thin film induced by low energy and high energy ion beam irradiation

Ratnesh Gupta, A. Khandelwal, D. K. Avasthi, K. G. M. Nair, and A. Gupta
Ion irradiation plays an important role to tailor the microcrystalline structure and the corresponding magnetic anisotropy by high local energy deposition and defect accumulation. In the present work, we have investigated the effects of nuclear energy loss and electronic energy loss on the phase tra ... [J. Appl. Phys. 107, 033902 (2010)] published Tue Feb 2, 2010.

Analysis of breakdown characteristics in high-k dielectrics under electrostatic discharge impulse stress

Chun-Heng Chen, Ming Han Liao, Fu-Chien Chiu, and Huey-Liang Hwang
Transmission line pulse measurements were used to investigate the reliability of the HfO dielectric under an electrostatic discharge event. Time-dependent dielectric breakdown of the gate oxide was characterized down to the microsecond time regime. The positive oxide-trapped charges Q were observed ... [J. Appl. Phys. 107, 034503 (2010)] published Tue Feb 2, 2010.

Analysis of multistate models for electromigration failure

V. M. Dwyer
The application of a multistate Markov chain is considered as a model of electromigration interconnect degradation and eventual failure. Such a model has already been used [Tan et al., J. Appl. Phys. 102, 103703 (2007)], maintaining that, in general, it leads to a failure distribution described by a ... [J. Appl. Phys. 107, 033709 (2010)] published Tue Feb 2, 2010.

Study of the Au Schottky contact formation on oxygen plasma treated n-type SnO (101) thin films

Takahiro Nagata, Oliver Bierwagen, Mark E. White, Min-Ying Tsai, and James S. Speck
As-grown and oxygen plasma treated n-type tin dioxide (SnO) (101) thin films were investigated regarding the properties of Au contacts, surface structure, and band bending. The plasma treatment was performed in a conventional oxygen plasma cleaning system with maximum oxygen ion energies of 400 eV. ... [J. Appl. Phys. 107, 033707 (2010)] published Tue Feb 2, 2010.

Erratum: Practical formulas for inner-shell ionization cross sections by electron impact: Applications in quantitative Auger electron spectroscopy [J. Appl. Phys. 106, 053706 (2009)]

A. Jablonski, F. Salvat, and C. J. Powell
Abstract not available. [J. Appl. Phys. 107, 039901 (2010)] published Tue Feb 2, 2010.

Femtosecond carrier dynamics in native and high resistivity iron-doped GaInAs

Suranjana Sengupta, Ingrid Wilke, and Partha. S. Dutta
We report femtosecond transient reflectivity measurements of as-grown and iron-doped GaInAs. A hybrid vertical Bridgman and gradient freezing directional solidification process was employed for the growth of high quality GaInAs:Fe crystals with the uniform impurity doping concentration necessary for ... [J. Appl. Phys. 107, 033104 (2010)] published Tue Feb 2, 2010.

Revealing microstructural inhomogeneities with dark-field neutron imaging

A. Hilger, N. Kardjilov, T. Kandemir, I. Manke, J. Banhart et al.
Dark-field neutron tomography was applied to obtain three-dimensional volumetric data representing the distribution of micrometer and submicrometer sized structures in bulk samples. This is a size range that complements the range of direct spatial resolution. A phase grating setup implemented in a c ... [J. Appl. Phys. 107, 036101 (2010)] published Mon Feb 1, 2010.

Optical constants of Cu(InGa)Se crystals

S. Levcenko, L. Duran, G. Gurieva, M. I. Alonso, E. Arushanov et al.
Spectroscopic ellipsometry has been used to characterize the dielectric functions of bulk Cu(InGa)Se crystals. Spectra were measured at room temperature over the energy range 0.745.2 eV. The dielectric functions as well as the complex refractive index, the absorption coefficient, and the normal-inci ... [J. Appl. Phys. 107, 033502 (2010)] published Mon Feb 1, 2010.

Dielectric, ferroelectric, piezoelectric, and electrostrictive properties of KNaNbO single crystals

Hana UrsiC, Andreja BenCan, Miha Skarabot, Matjaz Godec, and Marija Kosec
The dielectric, ferroelectric, piezoelectric, and electrostrictive properties of KNaNbO single crystals (KNN s.c.) prepared by solid-state crystal growth are reported. The dielectric constant (epsilon), dielectric losses (tan delta), remanent polarization (P), and coercive field (E) for KNN s.c. in ... [J. Appl. Phys. 107, 033705 (2010)] published Mon Feb 1, 2010.

The role of rare earth elements in the structures of FeB-based glass forming liquid alloys

S. P. Pan, J. Y. Qin, and T. K. Gu
The structures of liquid FeREB (RE=Sc, Er, Ho, Dy, Y, Sm, Gd, Nd, and Ce) alloys were investigated by ab initio molecular dynamics simulation. The results show that the chemical affinity of Fe-RE and RE-B may influence the glass forming ability more than the atomic size of RE atom in these alloys. A ... [J. Appl. Phys. 107, 033503 (2010)] published Mon Feb 1, 2010.

Effect of RuCoCr-oxide intermediate layers on the growth, microstructure, and recording performance of CoCrPtSiO perpendicular recording media

Kumar Srinivasan, S. N. Piramanayagam, and Yew Seng Kay
The crystallographic growth, magnetic properties, microstructure, and recording performance of CoCrPtSiO perpendicular magnetic recording media on RuCoCr type of intermediate layers were systematically investigated. Excellent Co (002) crystallographic texture with dispersion Deltatheta as low as 3.2 ... [J. Appl. Phys. 107, 033901 (2010)] published Mon Feb 1, 2010.

Optimization of the regenerator of a traveling-wave thermoacoustic refrigerator

Yuki Ueda, Bassem Mohamed Mehdi, Kohei Tsuji, and Atsushi Akisawa
Numerical investigations on the performance of a traveling-wave thermoacoustic refrigerator are described. This refrigerator consists of a looped tube attached to an acoustic driver. A regenerator with many narrow flow channels is installed in the looped tube. When acoustic power is supplied by the ... [J. Appl. Phys. 107, 034901 (2010)] published Mon Feb 1, 2010.

The preparation and ferroelectric properties of defect-free ultrathin films of vinylidene fluoride oligomer

Haisheng Xu, Guobing Li, Yanni Zhang, Xiuli Zhang, Yingjun Gu et al.
The ultrathin, defect-free ferroelectric films of vinylidene fluoride oligomer were fabricated by vapor deposition. A narrow substrate temperature window was found to get high quality ferroelectric films. Ferroelectric phase was obtained when the substrate temperature was 90 degrees C. The ferroele ... [J. Appl. Phys. 107, 034101 (2010)] published Mon Feb 1, 2010.

Tunneling magnetoresistance in Fe/MgO granular multilayers

A. Garcia-Garcia, A. Vovk, J. A. Pardo, P. Strichovanec, P. A. Algarabel et al.
We have investigated the transport and magnetotransport properties in Fe/MgO multilayers around the Fe percolation threshold as a function of the temperature and the nominal thickness of iron layer (t). Electrical resistivity measurements allowed us to disclose the charge transport mechanisms involv ... [J. Appl. Phys. 107, 033704 (2010)] published Mon Feb 1, 2010.

Luminescence, lifetime, and quantum yield studies of redispersible Eu-doped GdPO crystalline nanoneedles: Core-shell and concentration effects

N. Yaiphaba, R. S. Ningthoujam, N. Shanta Singh, R. K. Vatsa, N. Rajmuhon Singh et al.
Crystalline nanoneedles of Eu-doped GdPO and Eu-doped GdPO covered with GdPO shell (core shell) have been prepared at relatively low temperature of 150 degrees C in ethylene glycol medium. From luminescence study, asymmetric ratio of Eu emission at 612 nm (electric dipole transition) to 592 nm (mag ... [J. Appl. Phys. 107, 034301 (2010)] published Mon Feb 1, 2010.

Light polarization characteristics of m-plane AlGaN films suffering from in-plane anisotropic tensile stresses

K. Hazu, T. Hoshi, M. Kagaya, T. Onuma, and S. F. Chichibu
Polarization characteristics of the near-band-edge optical transitions in m-plane AlGaN epilayers suffering from anisotropic stresses were quantified. The epilayers were grown by both ammonia-source molecular beam epitaxy and metalorganic vapor phase epitaxy methods on an m-plane freestanding GaN su ... [J. Appl. Phys. 107, 033701 (2010)] published Mon Feb 1, 2010.

Origin of platelike granular structure for the ultrananocrystalline diamond films synthesized in H-containing Ar/CH plasma

Chuan-Sheng Wang, Huang-Chin Chen, Hsiu-Fung Cheng, and I-Nan Lin
The modification on microstructure of diamond films due to the incorporation of H species into the Ar/CH plasma was systematically investigated. While the hydrogen-free plasma produced the ultrananocrystalline diamond films with equiaxed grains (about 5 nm in size), the hydrogen-containing plasma re ... [J. Appl. Phys. 107, 034304 (2010)] published Mon Feb 1, 2010.

Ultralow threshold green lasing and optical bistability in ZBNA (ZrFBaFNaFAlF) microspheres

Yuqiang Wu (邬宇强), Jonathan M. Ward, and Sile Nic Chormaic
Upconversion lasing and fluorescence from active microspheres fabricated from a novel fluorozirconate, Er doped glass, ZBNA (ZrFBaFNaFAlF), when pumped at 978 nm via a tapered optical fiber is demonstrated. An ultralow, green lasing threshold of ~3 [mu]W for 550 nm emissions is measured. This is on ... [J. Appl. Phys. 107, 033103 (2010)] published Mon Feb 1, 2010.

Evolution of electron states at an n-type InSb surface in a depletion-layer formation process: Effect of nonparabolicity of the conduction-band dispersion

Noboru Takeshita and Takeshi Inaoka
Advancing adsorption on an n-type InSb(110) surface induces gradual formation of a carrier-depletion layer at the surface. Incorporating a highly nonparabolic (NP) dispersion of the conduction band into the local-density-functional formalism in a complete manner, we investigate evolution of electron ... [J. Appl. Phys. 107, 033702 (2010)] published Mon Feb 1, 2010.

Optical properties of ZnO/ZnMgO multiple quantum wells grown on (111) Si using buffer assisted pulsed-laser deposition

X. H. Pan, W. Guo, W. Tian, H. P. He, Z. Z. Ye et al.
This work investigates the photoluminescence properties of ZnO/ZnMgO multiple quantum wells (MQWs), which have been fabricated by pulsed-laser deposition on (111) Si substrates using intervening epitaxial LuO buffer layers. In ZnO/ZnMgO MQWs, the luminescence is dominated by localized exciton (LE) e ... [J. Appl. Phys. 107, 033102 (2010)] published Mon Feb 1, 2010.

Transition temperature in the growing of poly-Si/amorphous-SiO by electron-beam evaporation

Shao-Ji Jiang, Yu-Wei Wei, Zi-Yi Chen, and He-Zhou Wang
The transition temperature T in the growing of poly-Si thin film on amorphous-SiO, which is prepared by means of electron-beam evaporation (EBE), is evaluated through both simulation and experiment method. Our results demonstrate that there is a sudden transformation in the grain size at transition ... [J. Appl. Phys. 107, 034303 (2010)] published Mon Feb 1, 2010.

Macroscopic and nanoscale electrical properties of pulsed laser deposited (100) epitaxial lead-free NaBiTiO thin films

M. Bousquet, J.-R. Duclere, C. Champeaux, A. Boulle, P. Marchet et al.
Epitaxial NaBiTiO thin films presenting various thicknesses were grown by pulsed laser deposition on epitaxial (100) platinum bottom layers supported by (100)MgO single crystal substrates. X-ray diffraction data indicated that all NaBiTiO layers are single-phased and that (100)-oriented NaBiTiO (NBT ... [J. Appl. Phys. 107, 034102 (2010)] published Mon Feb 1, 2010.

Effect of surface roughness on thermal conductivity of silicon nanowires

Ling Liu and Xi Chen
Reducing the thermal conductivity of nanowires may enhance their already exciting efficiency of thermoelectric energy conversion. Using molecular dynamics simulations, we demonstrate that the thermal conductivity of silicon nanowires could be significantly decreased by patterning (or etching) induce ... [J. Appl. Phys. 107, 033501 (2010)] published Mon Feb 1, 2010.

Energy harvesting using a modified rectangular cymbal transducer based on 0.71Pb(MgNb)O0.29PbTiO single crystal

Bo Ren, Siu Wing Or, Xiangyong Zhao, and Haosu Luo
In this paper, we presented a modified rectangular cymbal transducer used as the vibration energy harvesting device based on 0.71Pb(MgNb)O0.29PbTiO single crystal. The vibration modes of the device were analyzed and the electrical properties were studied systematically. Under a cyclic force of 0.55 ... [J. Appl. Phys. 107, 034501 (2010)] published Mon Feb 1, 2010.

Electronic transport behaviors of NiNbZrH glassy alloys

M. Fukuhara, H. Yoshida, K. Koyama, A. Inoue, and Y. Miura
The electronic transport behaviors of (NiNbZr)H (0<=y<=20) glassy alloys with distorted nanostructural icosahedral ZrNbNi clusters have been studied as a function of hydrogen content. These alloys show semiconducting, room-temperature superior electric transport, superconducting (onset temperature ... [J. Appl. Phys. 107, 033703 (2010)] published Mon Feb 1, 2010.

Dielectrophoretic integration of single- and few-layer graphenes

Brian R. Burg, Julian Schneider, Simon Maurer, Niklas C. Schirmer, and Dimos Poulikakos
The dielectrophoretic integration of single- and few-layered graphenes from three distinct graphene suspensions is presented, enabling the parallel assembly of individual two-dimensional nanostructures at predefined locations. The first suspension is an aqueous solution of graphene oxide, the second ... [J. Appl. Phys. 107, 034302 (2010)] published Mon Feb 1, 2010.

Terahertz dielectric response and optical conductivity of n-type single-crystal ZnO epilayers grown by metalorganic chemical vapor deposition

X. H. Zhang, H. C. Guo, A. M. Yong, J. D. Ye, S. T. Tan et al.
Using terahertz time-domain spectroscopy, we measured the frequency dependent complex dielectric response and conductivity of n-type single-crystal ZnO epilayers with different carrier concentrations over the frequency range from 0.1 to 3.0 THz. The measured complex dielectric response and conductiv ... [J. Appl. Phys. 107, 033101 (2010)] published Mon Feb 1, 2010.

A compact model for polycrystalline pentacene thin-film transistor

Ling Li, Maarten Debucquoy, Jan Genoe, and Paul Heremans
A compact physical model for the operation of polycrystalline pentacene thin-film transistors is presented here, valid in both linear and saturation regimes by including the Gaussian energy distribution of the grain-boundary traps. The effect of the temperature is also taken into account. The propos ... [J. Appl. Phys. 107, 024519 (2010)] published Fri Jan 29, 2010.

Mechanics analysis and atomistic simulations of nanobridge tests

Wing Kin Chan and Tong-Yi Zhang
The present work carries out mechanics analysis and atomistic simulations of nanobridge tests under large deformation. The nanobridge test is a three-point bending test on a nanowire sample with two clamped ends. The bending behavior of a tested nanowire under large deformation is mechanically analy ... [J. Appl. Phys. 107, 023526 (2010)] published Fri Jan 29, 2010.

Controllable far-infrared electromagnetic radiation from plasmas applied by dc or ac bias electric fields

Wei-Min Wang, Zheng-Ming Sheng, X.-G. Dong, H.-W. Du, Y.-T. Li et al.
It is shown theoretically and numerically that a dc/ac bias field applied over tenuous plasma can be converted efficiently into electromagnetic (EM) waves at the plasma frequency omega, with the amplitude and polarization determined by the bias. The initial phase of the EM waves can be controlled by ... [J. Appl. Phys. 107, 023113 (2010)] published Fri Jan 29, 2010.

Quantum effect on modulational instability of laser radiation in a semiconductor plasma

M. R. Amin
Modulational instability of a high power laser radiation in a homogeneous unmagnetized piezoelectric semiconductor plasma has been investigated analytically. The fluid equations of quantum hydrodynamics coupled with the Maxwell's equations have been employed to find the nonlinear response of electro ... [J. Appl. Phys. 107, 023307 (2010)] published Fri Jan 29, 2010.

Probing porosity at buried interfaces using soft x-ray resonant reflectivity

Maheswar Nayak, G. S. Lodha, T. T. Prasad, P. Nageswararao, and A. K. Sinha
The optical constants of electron beam evaporated boron carbide are measured near boron K-absorption edge. Near the edge, the dispersion part of refractive index shows a sign reversal. Simulated reflectivity profiles near the absorption edge of boron are used to show the utility of soft x-ray resona ... [J. Appl. Phys. 107, 023529 (2010)] published Fri Jan 29, 2010.

High energy electron fluxes in dc-augmented capacitively coupled plasmas I. Fundamental characteristics

Mingmei Wang and Mark J. Kushner
Power deposition from electrons in capacitively coupled plasmas (CCPs) has components from stochastic heating, Joule heating, and from the acceleration of secondary electrons through sheaths produced by ion, electron, or photon bombardment of electrodes. The sheath accelerated electrons can produce ... [J. Appl. Phys. 107, 023308 (2010)] published Fri Jan 29, 2010.

Simplified procedure for interferometric determination of electro-optic properties of low-T photorefractive polymer

Takashi Fujihara, Takafumi Sassa, Takashi Kawada, Jun-ichi Mamiya, Tsuyoshi Muto et al.
A simplified procedure is proposed for the interferometric determination of optical dispersions of refractive-index changes in a low-T photorefractive (PR) polymer. A two-level model for the optical dispersions is used in order to separately evaluate the index changes occurring due to molecular bire ... [J. Appl. Phys. 107, 023112 (2010)] published Fri Jan 29, 2010.

In-plane phonon transport in thin films

J. E. Turney, A. J. H. McGaughey, and C. H. Amon
The in-plane phonon thermal conductivities of argon and silicon thin films are predicted from the Boltzmann transport equation under the relaxation time approximation. We model the thin films using bulk phonon properties obtained from harmonic and anharmonic lattice dynamics calculations. The input ... [J. Appl. Phys. 107, 024317 (2010)] published Fri Jan 29, 2010.

Left-handed transmission in a simple cut-wire pair structure

Nguyen Thanh Tung, Vu Tran Thanh Thuy, Jin Woo Park, Joo Yull Rhee, and YoungPak Lee
It is well known that, together with the plasma behavior of continuous wires, the use of cut-wire pair as a metamagnetic component is to drive the negative permeability in the left-handed combined structure. In this study, we have investigated a strange left-handed transmission in a metamaterial con ... [J. Appl. Phys. 107, 023530 (2010)] published Fri Jan 29, 2010.

Direct measurement of graphene adhesion on silicon surface by intercalation of nanoparticles

Zong Zong, Chia-Ling Chen, Mehmet R. Dokmeci, and Kai-tak Wan
We report a technique to characterize adhesion of monolayered/multilayered graphene sheets on silicon wafer. Nanoparticles trapped at graphene-silicon interface act as point wedges to support axisymmetric blisters. Local adhesion strength is found by measuring the particle height and blister radius ... [J. Appl. Phys. 107, 026104 (2010)] published Fri Jan 29, 2010.

Phonon sidebands of photoluminescence in single wall carbon nanotubes

Guili Yu, Qifeng Liang, Yonglei Jia, and Jinming Dong
The multiphonon-assisted photoluminescence (PL) of the single wall carbon nanotubes (SWNTs) have been studied by solving the Schrodinger equation, showing a set of phonon sidebands, both the Stokes and anti-Stokes lines, which are induced by the longitudinal optical phonon and radial breathing mode ... [J. Appl. Phys. 107, 024314 (2010)] published Fri Jan 29, 2010.

Charge ordering in PrCuMnO and its behavior under pressure

W. Zhang, L. D. Yao, L. X. Yang, Z. X. Liu, C. Q. Jin et al.
Polycrystalline PrCuMnO sample has been successfully synthesized. It has been characterized by x-ray diffraction (XRD), magnetic and magnetotransport measurements at ambient pressure, and transport property measurements under pressures. From the refinements of XRD data, a cubic phase and a trigonal ... [J. Appl. Phys. 107, 023914 (2010)] published Fri Jan 29, 2010.

Controlling blue-violet electroluminescence of Ge-rich Er-doped SiO layers by millisecond annealing using flash lamps

A. Kanjilal, L. Rebohle, M. Voelskow, M. Helm, and W. Skorupa
Systematic evolution of the 400 nm electroluminescence (EL) with increasing flash lamp annealing (FLA) temperature from 800 to 1100 degrees C in an Er-doped Ge-rich metal-oxide semiconductor structure is presented. No significant change in the 1535 nm Er EL is observed with increasing FLA temperatu ... [J. Appl. Phys. 107, 023114 (2010)] published Fri Jan 29, 2010.

Different origins of the yellow luminescence in as-grown high-resistance GaN and unintentional-doped GaN films

F. J. Xu, B. Shen, L. Lu, Z. L. Miao, J. Song et al.
The yellow luminescence (YL) in as-grown high-resistance (HR) and unintentional-doped (UID) GaN films grown by metal organic chemical vapor deposition has been investigated by means of photoluminescence and monoenergetic positron annihilation spectroscopy. It is found there is stronger YL in UID-GaN ... [J. Appl. Phys. 107, 023528 (2010)] published Fri Jan 29, 2010.

Analysis of mass transport in an atmospheric pressure remote plasma-enhanced chemical vapor deposition process

R. P. Cardoso, T. Belmonte, G. Henrion, T. Gries, and E. Tixhon
In remote microwave plasma enhanced chemical vapor deposition processes operated at atmospheric pressure, high deposition rates are associated with the localization of precursors on the treated surface. We show that mass transport can be advantageously ensured by convection for the heavier precursor ... [J. Appl. Phys. 107, 024909 (2010)] published Fri Jan 29, 2010.

Submolecular-scale Investigations on metal-phthalocyanine monolayers by frequency modulation atomic force microscopy

Takashi Ichii, Takeshi Fukuma, Tadashi Yoda, Kei Kobayashi, Kazumi Matsushige et al.
Copper-phthalocyanine (CuPc) monolayers and cobalt-phthalocyanine monolayers deposited on Au(111) surfaces were investigated by frequency modulation atomic force microscopy (FM-AFM). Submolecular-resolution topographic images were successfully obtained for both samples. Despite the similar molecular ... [J. Appl. Phys. 107, 024315 (2010)] published Fri Jan 29, 2010.

Bulk waves excited by a laser line pulse in a two-layered cylinder

Y. Pan, N. Chigarev, and B. Audoin
The acoustic displacements excited by a laser line source under either the ablation or thermoelastic regime are calculated for a two-layered cylinder made of homogeneous and isotropic materials. Two samples made by welding tin in two different copper tubes are considered. Experimental displacements ... [J. Appl. Phys. 107, 023527 (2010)] published Fri Jan 29, 2010.

High energy electron fluxes in dc-augmented capacitively coupled plasmas. II. Effects on twisting in high aspect ratio etching of dielectrics

Mingmei Wang and Mark J. Kushner
In high aspect ratio (HAR) plasma etching of holes and trenches in dielectrics, sporadic twisting is often observed. Twisting is the randomly occurring divergence of a hole or trench from the vertical. Many causes have been proposed for twisting, one of which is stochastic charging. As feature sizes ... [J. Appl. Phys. 107, 023309 (2010)] published Fri Jan 29, 2010.

Luminescence properties of the solvothermally synthesized blue light emitting Mn doped CuO nanoparticles

Kajari Das, Shailesh N. Sharma, Mahesh Kumar, and S. K. De
The CuO nanoparticles having average crystallite diameters ~816 nm were synthesized by a simple solvothermal method. The Mn was doped in the CuO sample of crystallite size ~8 nm. The effects of the size and doping concentration on the crystal structures of the nanoparticles were investigated. The ... [J. Appl. Phys. 107, 024316 (2010)] published Fri Jan 29, 2010.

Comparison of electrical, optical, structural, and interface properties of IZO-Ag-IZO and IZO-Au-IZO multilayer electrodes for organic photovoltaics

Jin-A Jeong, Yong-Seok Park, and Han-Ki Kim
We compared the electrical, optical, structural, and interface properties of indium zinc oxide (IZO)-Ag-IZO and IZO-Au-IZO multilayer electrodes, as well as the dependence of their electrical and optical properties on the thicknesses of the Ag and Au layers when used for organic solar cells (OSCs). ... [J. Appl. Phys. 107, 023111 (2010)] published Fri Jan 29, 2010.

Increased size selectivity of Si quantum dots on SiC at low substrate temperatures: An ion-assisted self-organization approach

D. H. Seo, A. E. Rider, A. Das Arulsamy, I. Levchenko, and K. Ostrikov
A simple, effective, and innovative approach based on ion-assisted self-organization is proposed to synthesize size-selected Si quantum dots (QDs) on SiC substrates at low substrate temperatures. Using hybrid numerical simulations, the formation of Si QDs through a self-organization approach is inve ... [J. Appl. Phys. 107, 024313 (2010)] published Thu Jan 28, 2010.

Modified spontaneous emission rate in three-dimensional layer-by-layer photonic crystals with planar defects

Ji-Feng Chen, Rong-Tai Hong, and Jaw-Yen Yang
A finite three-dimensional layer-by-layer photonic crystal with planar defects in a layer is shown to drastically modify the spontaneous emission rate of an embedded dipole. Finite-difference time-domain calculations with one quarter symmetric boundary condition and perfectly matched layer demonstra ... [J. Appl. Phys. 107, 023110 (2010)] published Thu Jan 28, 2010.

Optical doping and damage formation in AlN by Eu implantation

K. Lorenz, E. Alves, F. Gloux, P. Ruterana, M. Peres et al.
AlN films grown on sapphire were implanted with 300 keV Eu ions to fluences from 3 x 10 to 1.4 x 10 atoms/cm in two different geometries: channeled along the c-axis and random with a 10 degrees angle between the ion beam and the surface normal. A detailed study of implantation damage accumulation ... [J. Appl. Phys. 107, 023525 (2010)] published Thu Jan 28, 2010.

The influence of aluminum grain size on alumina nanoporous structure

A. F. Feil, M. V. da Costa, L. Amaral, S. R. Teixeira, P. Migowski et al.
An approach to control the interpore distances and nanopore diameters of 150-nm-thick thin aluminum films is reported here. The Al thin films were grown by sputtering on p-type silicon substrate and anodized with a conventional anodization process in a phosphoric acid solution. It was found that int ... [J. Appl. Phys. 107, 026103 (2010)] published Thu Jan 28, 2010.

Effect of the external fields on the polar and dielectric properties of EuYMnO

J. Agostinho Moreira, A. Almeida, W. S. Ferreira, M. R. Chaves, S. M. F. Vilela et al.
EuYMnO has been widely studied due to its very distinctive phase diagram, where it is still poorly understood the actual ferroelectric character of the low temperature magnetic phases. In order to figure out what is the origin of the microscopic mechanisms that drive its behavior, we carried out a d ... [J. Appl. Phys. 107, 024108 (2010)] published Thu Jan 28, 2010.

Directional emissions achieved with anomalous reflection phases of metamaterials

Kun Ding, Tao Jiang, Jiaming Hao, Lixin Ran, and Lei Zhou
For a small antenna placed on a metamaterial ground plane vertically or horizontally, we analyzed the conditions under which the antenna emissions are highly directional. We found through finite-difference time-domain (FDTD) simulations that a previously discovered directional emission phenomenon ca ... [J. Appl. Phys. 107, 023109 (2010)] published Thu Jan 28, 2010.

Optical properties of AlGaN alloy

Katsuki Takeuchi, Sadao Adachi, and Kohji Ohtsuka
The optical response of the AlGaN alloy has been analyzed using a simplified model of interband transitions (E<=10 eV). The present model reveals distinct structures at energies of the E, E, F, and E critical points. The CauchyLorentz expression popularly used for the modeling of the three-dimensio ... [J. Appl. Phys. 107, 023306 (2010)] published Thu Jan 28, 2010.

Nearly complete isobar suppression by photodetachment

P. Andersson, A. O. Lindahl, D. Hanstorp, C. C. Havener, Yun Liu et al.
The efficiency of selective suppression of negative ions by photodetachment in a gas-filled radio frequency quadrupole ion cooler was investigated with a new detection method. A neodymium doped yttrium aluminum garnet laser beam at 1064 nm was used to remove Co ions in the radio frequency quadrupole ... [J. Appl. Phys. 107, 026102 (2010)] published Thu Jan 28, 2010.

Modeling the single-gate, double-gate, and gate-all-around tunnel field-effect transistor

Anne S. Verhulst, Bart Soree, Daniele Leonelli, William G. Vandenberghe, and Guido Groeseneken
Tunnel field-effect transistors (TFETs) are potential successors of metal-oxide-semiconductor FETs because scaling the supply voltage below 1 V is possible due to the absence of a subthreshold-swing limit of 60 mV/decade. The modeling of the TFET performance, however, is still preliminary. We have d ... [J. Appl. Phys. 107, 024518 (2010)] published Thu Jan 28, 2010.

Enhanced leakage current properties of Ni-doped BaSrTiO thin films driven by modified band edge state

Hyungtak Seo, Young-Bae Kim, Gerald Lucovsky, Il-Doo Kim, Kwun-Bum Chung et al.
1% Ni-doped barium strontium titanate (BST) thin film deposited at room temperature reveals the significantly enhanced leakage current performance which is extraordinarily effective for low temperature applications. Significant leakage current suppression of >2 orders was achieved for electric field ... [J. Appl. Phys. 107, 024109 (2010)] published Thu Jan 28, 2010.

Nonlinear characterization of GeSSbSCsI glass system

K. Fedus, G. Boudebs, Q. Coulombier, J. Troles, and X. H. Zhang
We present the results of Z-scan measurements (1064 nm, 17 ps) of nonlinear refractive indices and nonlinear absorption coefficients for different compositions of chalcogenide glasses in GeSSbSCsI system. We show that the simple well known Boling, Glass, and Owyoung model based on the theory of the ... [J. Appl. Phys. 107, 023108 (2010)] published Thu Jan 28, 2010.

A metal-to-insulator transition in cut-wire-grid metamaterials in the terahertz region

Keisuke Takano, Kyoji Shibuya, Koichi Akiyama, Takeshi Nagashima, Fumiaki Miyamaru et al.
Metamaterials with metallic wire-gird structures support extremely low frequency plasmons and their electromagnetic responses exhibit metallic characteristics described by the Drude model. In this paper, we have investigated the electromagnetic responses of the wire-grid structures in the terahertz ... [J. Appl. Phys. 107, 024907 (2010)] published Wed Jan 27, 2010.

Low-frequency acoustic absorption of localized resonances: Experiment and theory

Honggang Zhao, Jihong Wen, Dianlong Yu, and Xisen Wen
The idea of localized resonance in phononic crystals is introduced to improve the low-frequency acoustic absorption of viscoelastic materials, which are widely used underwater to absorb the unwanted noise and meet a difficult challenge to enhance low-frequency absorption. Experimental measurements f ... [J. Appl. Phys. 107, 023519 (2010)] published Wed Jan 27, 2010.

Electrical and optical properties of Fe doped AlGaN grown by molecular beam epitaxy

A. Y. Polyakov, N. B. Smirnov, A. V. Govorkov, E. A. Kozhukhova, A. M. Dabiran et al.
Electrical and optical properties of AlGaN grown by molecular beam epitaxy were studied in the Al composition range 15%45%. Undoped films were semi-insulating, with the Fermi level pinned near E-0.60.7 eV. Si doping to (57) x 10 cm rendered the 15% Al films conducting n-type, but a large portion o ... [J. Appl. Phys. 107, 023708 (2010)] published Wed Jan 27, 2010.

Two-dimensional imaging of thermal diffusivity in metals by scanning photodeflection detection

Ulises Crossa Archiopoli, Nelida Mingolo, and Oscar E. Martinez
We present a technique that retrieves the thermal diffusivity of metallic samples in a two-dimensional map with micrometer resolution. The technique uses a photothermal method based on the deflection of a probe beam after heating the surface with a modulated pump. After adequate calibration, the tim ... [J. Appl. Phys. 107, 023520 (2010)] published Wed Jan 27, 2010.

Coexistence of the bipolar and unipolar resistive-switching modes in NiO cells made by thermal oxidation of Ni layers

L. Goux, J. G. Lisoni, M. Jurczak, D. J. Wouters, L. Courtade et al.
In this paper, we show the coexistence of the bipolar and unipolar resistive-switching modes in NiO cells realized using an optimized oxidation process of a Ni blanket layer used as the bottom electrode. The two switching modes can be activated independent of the cell switching history provided the ... [J. Appl. Phys. 107, 024512 (2010)] published Wed Jan 27, 2010.

Probing Cu doped GeSe based resistance switching memory devices with random telegraph noise

R. Soni, P. Meuffels, A. Petraru, M. Weides, C. Kugeler et al.
The ultimate sensitivity of any solid state device is limited by fluctuations. Fluctuations are manifestations of the thermal motion of matter and the discreteness of its structure which are also inherent ingredients during the resistive switching process of resistance random access memory (RRAM) de ... [J. Appl. Phys. 107, 024517 (2010)] published Wed Jan 27, 2010.

Possible origin of photoconductivity in LaCaMnO

P. R. Sagdeo, R. J. Choudhary, and D. M. Phase
The effect of photon energy on the density of states near Fermi level of pulsed laser deposited LaCaMnO thin film has been studied to investigate the possible origin of change in the conductivity of these manganites upon photon exposure. For this purpose the photoelectron spectroscopy measurements w ... [J. Appl. Phys. 107, 023709 (2010)] published Wed Jan 27, 2010.

Lithium related deep and shallow acceptors in Li-doped ZnO nanocrystals

C. Rauch, W. Gehlhoff, M. R. Wagner, E. Malguth, G. Callsen et al.
We study the existence of Li-related shallow and deep acceptor levels in Li-doped ZnO nanocrystals using electron paramagnetic resonance (EPR) and photoluminescence (PL) spectroscopy. ZnO nanocrystals with adjustable Li concentrations between 0% and 12% have been prepared using organometallic precur ... [J. Appl. Phys. 107, 024311 (2010)] published Wed Jan 27, 2010.

Characterization of thin metal films via frequency-domain thermoreflectance

Aaron J. Schmidt, Ramez Cheaito, and Matteo Chiesa
Frequency-domain thermoreflectance is extended to the characterization of thin metals films on low thermal diffusivity substrates. We show how a single noncontact measurement can yield both the thickness and thermal conductivity of a thin metal film with high accuracy. Results are presented from mea ... [J. Appl. Phys. 107, 024908 (2010)] published Wed Jan 27, 2010.

The drift-diffusion interpretation of the electron current within the organic semiconductor characterized by the bulk single energy trap level

B. Cvikl
The closed solution for the internal electric field and the total charge density derived in the drift-diffusion approximation for the model of a single layer organic semiconductor structure characterized by the bulk shallow single trap-charge energy level is presented. The solutions for two examples ... [J. Appl. Phys. 107, 023710 (2010)] published Wed Jan 27, 2010.

Positron annihilation study of the interfacial defects in ZnO nanocrystals: Correlation with ferromagnetism

Dong Wang, Z. Q. Chen, D. D. Wang, N. Qi, J. Gong et al.
High purity ZnO nanopowders were pressed into pellets and annealed in air between 100 and 1200 degrees C. The crystal quality and grain size of the ZnO nanocrystals were investigated by x-ray diffraction 2theta scans. Annealing induces an increase in the grain size from 25 to 165 nm with temperatur ... [J. Appl. Phys. 107, 023524 (2010)] published Wed Jan 27, 2010.

A model for radiation-induced off-state leakage current in N-channel metal-oxide-semiconductor transistors with shallow trench isolation

Sihao Wang, Yunpeng Pei, Ru Huang, Wenhua Wang, Wen Liu et al.
A radiation-induced leakage current model in deep submicron bulk silicon N-channel metal-oxide-semiconductor field effect transistor (NMOSFET) is proposed in this paper for circuit simulations. The model takes into account the impact of the substrate doping concentration, the angle of shallow trench ... [J. Appl. Phys. 107, 024515 (2010)] published Wed Jan 27, 2010.

Ni doping of semiconducting boron carbide

Nina Hong (이니나), M. A. Langell, Jing Liu, Orhan Kizilkaya, and S. Adenwalla
The wide band gap, temperature stability, high resistivity, and robustness of semiconducting boron carbide make it an attractive material for device applications. Undoped boron carbide is p type; Ni acts as a n-type dopant. Here we present the results of controlled doping of boron carbide with Ni on ... [J. Appl. Phys. 107, 024513 (2010)] published Wed Jan 27, 2010.

O-vacancy-mediated spin-spin interaction in Co-doped ZnO: First-principles total-energy calculations

En-Zuo Liu and J. Z. Jiang
The effects of O vacancy (V) on the electronic and magnetic properties of Co-doped ZnO are examined through first-principles total-energy calculations. Our results suggest that due to the presence of V, O 2p states are coupled with the Co 3d states. Co 3d empty minority states are broadened and move ... [J. Appl. Phys. 107, 023909 (2010)] published Wed Jan 27, 2010.

Time resolved imaging of carrier and thermal transport in silicon

D. H. Hurley, O. B. Wright, O. Matsuda, and S. L. Shinde
We use ultrashort optical pulses to microscopically image carrier and thermal diffusion in two spatial dimensions in pristine and mechanically polished surfaces of crystalline silicon. By decomposing changes in reflectivity in the latter sample into a transient component that varies with delay time ... [J. Appl. Phys. 107, 023521 (2010)] published Wed Jan 27, 2010.

Tunable rectification and giant positive magnetoresistance in GeMn/Ge epitaxial heterojunction diodes

Y. F. Tian, J. X. Deng, S. S. Yan, Y. Y. Dai, M. W. Zhao et al.
GeMn/Ge single-crystal heterojunction diodes with p-type GeMn ferromagnetic semiconductor were grown, respectively on Ge substrates of p-type, n-type, and intrinsic semiconductors by molecular beam epitaxy. The I-V curve of the p-GeMn/intrinsic-Ge diode can be greatly tuned by a magnetic field, whic ... [J. Appl. Phys. 107, 024514 (2010)] published Wed Jan 27, 2010.

Perpendicular magnetization behaviors of Co/FeMn/Co multilayers with and without Pt spacer

Y. Liu, Y. Q. Fu, S. Liu, C. Jin, M. H. Li et al.
The interfacial effect on the magnetization in the magnetron sputtered Co/FeMn/Co multilayers with Pt spacer layer upon and beneath the FeMn layer, respectively, was investigated. The variation in the magnetization with the thickness of the Co layer strongly depends on the orientation and the rotati ... [J. Appl. Phys. 107, 023912 (2010)] published Wed Jan 27, 2010.

Evolution of residual-strain distribution through an overload-induced retardation period during fatigue-crack growth

S. Y. Lee, Y. Sun, K. An, H. Choo, C. R. Hubbard et al.
Neutron diffraction was employed to investigate the crack-growth retardation phenomenon after a single tensile overload by mapping both one-dimensional and two-dimensional residual-strain distributions around the crack tip in a series of compact-tension specimens representing various crack-growth st ... [J. Appl. Phys. 107, 023517 (2010)] published Wed Jan 27, 2010.

Optical properties of InGaN/GaN nanopillars fabricated by postgrowth chemically assisted ion beam etching

Y. Kawakami, A. Kaneta, L. Su, Y. Zhu, K. Okamoto et al.
The optical properties of InGaN/GaN quantum wells, which were nanopatterned into cylindrical shapes with diameters of 2 [mu]m, 1 [mu]m, or 500 nm by chemically assisted ion beam etching, were investigated. Photoluminescence (PL) and time-resolved PL measurements suggest inhomogeneous relaxation of ... [J. Appl. Phys. 107, 023522 (2010)] published Wed Jan 27, 2010.

Photopolymerization kinetics and volume holographic recording in ZrO nanoparticle-polymer composites at 404 nm

Koji Omura and Yasuo Tomita
We investigate volume holographic recording in a ZrO nanoparticle-polymer composite film at a wavelength of 404 nm. Dependences of the polymerization kinetics on concentrations of an initiator and ZrO nanoparticles doped in acrylate monomer are examined by using a photodifferential scanning calorime ... [J. Appl. Phys. 107, 023107 (2010)] published Wed Jan 27, 2010.

Exchange bias in Fe and Ni codoped CuO nanocomposites

K. L. Liu, S. L. Yuan, H. N. Duan, X. F. Zheng, S. Y. Yin et al.
Exchange bias nanocomposites were obtained by the chemical concentration precipitation method, in which the ferrimagnetic MFeO (M=Cu,Ni) particles were embedded in the antiferromagnetic (AFM) CuO matrix. The dependence of magnetization on temperature measurements show that the exchange bias effect i ... [J. Appl. Phys. 107, 023911 (2010)] published Wed Jan 27, 2010.

Application-oriented nitride substrates: The key to long-wavelength nitride lasers beyond 500 nm

T. K. Sharma and E. Towe
We present results based on quantum mechanical estimates of the longest emission wavelength for nitride laser diodes grown on c-plane GaN/sapphire substrates. The results indicate that the absence of polarization-induced electric fields in nonpolar/semipolar GaN substrates does not necessarily guara ... [J. Appl. Phys. 107, 024516 (2010)] published Wed Jan 27, 2010.

Bias stress voltage dependence for fast and slow traps resulting in negative bias temperature instability

J. K. Mee and R. A. B. Devine
We have studied the bias stressing voltage dependence of the negative bias temperature instability (NBTI) in p-channel field effect transistors with nominal SiON/HfSiON gate stacks. Measurements were made at the temperature of 448 K. Three different methods were used to extract device parameters suc ... [J. Appl. Phys. 107, 024511 (2010)] published Wed Jan 27, 2010.

Effective viscosity of semidilute suspensions of rigid ellipsoids

C. H. Hsueh and W. C. J. Wei
Hard and refractory particles with various shapes have been added to ceramic materials to enhance creep resistance. Also, many of the particles in food emulsions, magnetic particle suspensions, and other industrial systems may have nonspherical shapes. Hence, it is important to understand the effect ... [J. Appl. Phys. 107, 024905 (2010)] published Wed Jan 27, 2010.

Electrical transport mechanisms in a-Si:H/c-Si heterojunction solar cells

T. F. Schulze, L. Korte, E. Conrad, M. Schmidt, and B. Rech
We present temperature-dependent measurements of I-V curves in the dark and under illumination in order to elucidate the dominant transport mechanisms in amorphous silicon-crystalline silicon (a-Si:H/c-Si) heterojunction solar cells. ZnO:Al/(p)a-Si:H/(n)c-Si/(n)a-Si:H cells are compared with inverse ... [J. Appl. Phys. 107, 023711 (2010)] published Wed Jan 27, 2010.

Pulsed-laser treatment of solution-grown ZnO nanowires in nitrogen: Enhancing in electrical conduction and field emission

J. B. Chen, C. J. Xu, J. C. She, S. Z. Deng, Jun Chen et al.
Pulsed-laser (neodymium doped yttrium aluminum garnet; 1.06 [mu]m in wavelength) treatments were performed on zinc oxide (ZnO) nanowires (NWs) in nitrogen. It results in nitrogen doping of ZnO, mainly with chemical states of N at oxygen sites, which is demonstrated by x-ray photoelectron spectrosco ... [J. Appl. Phys. 107, 024312 (2010)] published Wed Jan 27, 2010.

Raman and Fourier transform infrared study of substitutional carbon incorporation in rapid thermal chemical vapor deposited SiGeC on (1 0 0) Si

Joanna Wasyluk, Tatiana S. Perova, and Francoise Meyer
We report on a detailed study of the dependence of the vibrational modes in rapid thermal chemical vapor deposited SiGeC films on the substitutional carbon concentration. SiGeC films were investigated using Raman and infrared spectroscopy with x varying in the range of 10%16% and y in the range of 0 ... [J. Appl. Phys. 107, 023518 (2010)] published Wed Jan 27, 2010.

Magnetotransport behavior of Co nanowires coupled to NiFe films

S. Goolaup, A. O. Adeyeye, and N. Singh
We have fabricated and characterized hybrid-trilayer ferromagnetic structures comprising of 60-nm-thick NiFe (Py) film grown on top of patterned array of 60-nm-thick Co nanowires (NWs) with Cu spacer layer. The hybrid structures display unique magnetic and transport properties due to the nonuniform ... [J. Appl. Phys. 107, 023913 (2010)] published Wed Jan 27, 2010.

Transfer of InP thin films from engineered porous silicon substrates

Monali B. Joshi and Mark S. Goorsky
Engineered composite substrates for thin film layer transfer applications are fabricated by incorporating the techniques of anodic etching, wafer bonding, and hydrogen-induced exfoliation. Silicon substrates (p/p) are subjected to anodic electrochemical etching in 25% HF electrolyte to create double ... [J. Appl. Phys. 107, 024906 (2010)] published Wed Jan 27, 2010.

Band-gap nonlinearity in perovskite structured solid solutions

Soonil Lee, Roni D. Levi, Weiguo Qu, Sung Chan Lee, and Clive A. Randall
Compositional effects on optical band-gap energy using end members of ABO perovskites have been investigated through an optical absorption with a UV-spectroscopy. Three examples are selected, namely, BaTiOCaTiO, BaTiOBaZrO, and SrTiOBaZrO solid solutions. To understand the role of high temperature p ... [J. Appl. Phys. 107, 023523 (2010)] published Wed Jan 27, 2010.

Impact of viscous flux flow on the stress in long rectangular slab superconductors

Yong Yang, Li-Ye Xiao, and Xiao-Hang Li
We have attempted to resolve the influence of the rate (dB/dt), at which an external magnetic field B is swept down, on the tensile stress in bulk type-II superconductors. The effect of viscous flux velocity (upsilon) on the stress is discussed for two magnetization processes: the decreasing field a ... [J. Appl. Phys. 107, 023910 (2010)] published Wed Jan 27, 2010.

Influence of the salinity on the characteristics of acoustic signal in salt water generated by pulsed CO laser

Haihong Zhu, Qingming Chen, Zuhai Cheng, and Huiqun Tang
The experimental study on the laser acoustic signal in salt water with different salinities using high power pulsed CO laser has been carried out. By using a hydrophone to receive the sound signal and further analyzing in time domain, the effects of the salinity and pulse energy on the characteristi ... [J. Appl. Phys. 107, 023106 (2010)] published Wed Jan 27, 2010.