JAP: Structural, Mechanical, Thermodynamic, and Optical Properties of Condensed Matter http://scitation.aip.org/ JAP: Structural, Mechanical, Thermodynamic, and Optical Properties of Condensed Matter Origin of 2.7 [mu]m luminescence and energy transfer process of Er: I-->I transition in Er/Yb doped germanate glasses http://link.aip.org/link/?JAP/111/033524/1&agg=rss Rongrong Xu<!--orlang--> (&#x5F90;&#x8338;&#x8338;)<!--orlang-->, Ying Tian<!--orlang--> (&#x7530;&#x9896;)<!--orlang-->, Lili Hu<!--orlang--> (&#x80E1;&#x4E3D;&#x4E3D;)<!--orlang-->, and Junjie Zhang<!--orlang--> (&#x5F20;&#x519B;&#x6770;)<!--orlang--><br/> An investigation of spectroscopic property and energy transfer process of Er doped and Er/Yb co-doped germanate glasses is presented. The emission cross section of the I --> I transition of Er doped germanate glass is calculated to be 1.2 x 10 cm. The microparameter of energy transfer from Yb: F t ... [J. Appl. Phys. 111, 033524 (2012)] published Mon Feb 13, 2012. Observation and simulation of hard x ray photoelectron diffraction to determine polarity of polycrystalline zinc oxide films with rotation domains http://link.aip.org/link/?JAP/111/033525/1&agg=rss Jesse R. Williams, Igor Pis, Masaaki Kobata, Aimo Winkelmann, Tomohiro Matsushita et al.<br/> X ray photoelectron diffraction (XPD) patterns of polar zinc oxide (ZnO) surfaces were investigated experimentally using hard x rays and monochromatized Cr Kalpha radiation and theoretically using a cluster model approach and a dynamical Bloch wave approach. We focused on photoelectrons emitted from ... [J. Appl. Phys. 111, 033525 (2012)] published Mon Feb 13, 2012. Thickness effects on the texture development of fluorine-doped SnO thin films: The role of surface and strain energy http://link.aip.org/link/?JAP/111/033523/1&agg=rss V. Consonni, G. Rey, H. Roussel, and D. Bellet<br/> Polycrystalline fluorine-doped SnO thin films have been grown by ultrasonic spray pyrolysis with a thickness varying in the range of 40 to 600 nm. A texture transition from to and crystallographic orientations has experimentally been shown by x-ray diffraction measurements as film thickness is in ... [J. Appl. Phys. 111, 033523 (2012)] published Mon Feb 13, 2012. Surface diffusion and layer morphology of ((11[overline 2]2)) GaN grown by metal-organic vapor phase epitaxy http://link.aip.org/link/?JAP/111/033526/1&agg=rss Simon Ploch, Tim Wernicke, Duc V. Dinh, Markus Pristovsek, and Michael Kneissl<br/> (11[overline 2]2) GaN layers were grown by metal-organic vapor phase epitaxy on (11[overline 2]2) bulk GaN substrates and (10[overline 1]0) sapphire substrates. The growth temperature was varied between 950 and 1050 degrees C and the total reactor pressure between 50 and 600 mbar. The growth condit ... [J. Appl. Phys. 111, 033526 (2012)] published Mon Feb 13, 2012. First-principles investigation of pressure-induced phase transition in LiNbO http://link.aip.org/link/?JAP/111/033522/1&agg=rss Kaoru Nakamura, Sadao Higuchi, and Toshiharu Ohnuma<br/> We explore the possible high-pressure phase transition of LiNbO using an evolutionary algorithm combined with first-principles calculations. A NaIO-type structure with Pnma symmetry was predicted as the room temperature phase, and an apatite-like structure with P6/m symmetry was predicted as the hig ... [J. Appl. Phys. 111, 033522 (2012)] published Fri Feb 10, 2012. Grown-in precipitates in heavily phosphorus-doped Czochralski silicon http://link.aip.org/link/?JAP/111/033520/1&agg=rss Yuheng Zeng, Xiangyang Ma, Jiahe Chen, Weijie Song, Weiyan Wang et al.<br/> Through comparing the oxygen precipitation in the heavily and lightly phosphorus (P)-doped Czochralski silicon (CZ Si) specimens subjected to the simulated cooling processes of silicon ingot, we researched the influences of heavily P doping on grown-in precipitates by preferential etching and transm ... [J. Appl. Phys. 111, 033520 (2012)] published Thu Feb 9, 2012. Molecular dynamics simulations of damage production by thermal spikes in Ge http://link.aip.org/link/?JAP/111/033519/1&agg=rss Pedro Lopez, Lourdes Pelaz, Ivan Santos, Luis A. Marques, and Maria Aboy<br/> Molecular dynamics simulation techniques are used to analyze damage production in Ge by the thermal spike process and to compare the results to those obtained for Si. As simulation results are sensitive to the choice of the inter-atomic potential, several potentials are compared in terms of material ... [J. Appl. Phys. 111, 033519 (2012)] published Thu Feb 9, 2012. Prediction of glass-forming ability and characterization of atomic structure of the Co-Ni-Zr metallic glasses by a proposed long range empirical potential http://link.aip.org/link/?JAP/111/033521/1&agg=rss Dai Ye, Li Jiahao, and Liu Baixin<br/> An interatomic potential is constructed for the Co-Ni-Zr ternary metal system under long range empirical formalism and applied to conduct molecular dynamics simulations and Voronoi tessellations. Using solid solution models with varying solute concentrations, the simulations reveal that the physical ... [J. Appl. Phys. 111, 033521 (2012)] published Thu Feb 9, 2012. Structural properties and spatial ordering in multilayered ZnMgTe/ZnSe type-II quantum dot structures http://link.aip.org/link/?JAP/111/033516/1&agg=rss U. Manna, I. C. Noyan, Q. Zhang, I. F. Salakhutdinov, K. A. Dunn et al.<br/> We report the structural properties and spatial ordering of multilayer ZnMgTe quantum dots (QDs) embedded in ZnSe, where sub-monolayer quantities of Mg were introduced periodically during growth in order to reduce the valence band offset of ZnTe QDs. The periodicity, period dispersion, individual la ... [J. Appl. Phys. 111, 033516 (2012)] published Wed Feb 8, 2012. Thermal carrier emission and nonradiative recombinations in nonpolar (Al,Ga)N/GaN quantum wells grown on bulk GaN http://link.aip.org/link/?JAP/111/033517/1&agg=rss P. Corfdir, A. Dussaigne, H. Teisseyre, T. Suski, I. Grzegory et al.<br/> We investigate, via time-resolved photoluminescence, the temperature-dependence of charge carrier recombination mechanisms in nonpolar (Al,Ga)N/GaN single quantum wells (QWs) grown via molecular beam epitaxy on the a-facet of bulk GaN crystals. We study the influence of both QW width and barrier Al ... [J. Appl. Phys. 111, 033517 (2012)] published Wed Feb 8, 2012. Ab initio investigations of phonons and superconductivity in the cubic Laves structures LaAl and YAl http://link.aip.org/link/?JAP/111/033514/1&agg=rss S. Duman and H. M. Tutuncu<br/> We have performed an ab initio study of structural, elastic, electronic, lattice-dynamical, and electron-phonon interaction properties of the cubic Laves structures LaAl and YAl. The calculations have been carried out within the density-functional theory and linear response formalism using pseudopot ... [J. Appl. Phys. 111, 033514 (2012)] published Wed Feb 8, 2012. Formation of twins in sapphire under shock wave loading: Atomistic simulations http://link.aip.org/link/?JAP/111/033513/1&agg=rss A. Yu. Kuksin and A. V. Yanilkin<br/> This work is devoted to molecular dynamics (MD) simulation of shock-wave loading of sapphire (alpha-AlO). Defect free sapphire and sapphire with the microcrack are considered. Homogeneous nucleation and growth of rhombohedral twins are observed in single crystal alumina. A fast mechanism of plastic ... [J. Appl. Phys. 111, 033513 (2012)] published Wed Feb 8, 2012. High temperature annealing of n-type 4H-SiC: Impact on intrinsic defects and carrier lifetime http://link.aip.org/link/?JAP/111/033515/1&agg=rss Bernd Zippelius, Jun Suda, and Tsunenobu Kimoto<br/> In this paper, the impact of high-temperature annealing of 4H silicon carbide (SiC) on the formation of intrinsic defects, such as Z and EH, and on carrier lifetimes was studied. Four nitrogen-doped epitaxial layers with various initial concentrations of the Z- and EH-centers (10-10cm) were investig ... [J. Appl. Phys. 111, 033515 (2012)] published Wed Feb 8, 2012. Thermodynamic, Raman and electrical switching studies on SiTeAg (4 <= x <= 20) glasses http://link.aip.org/link/?JAP/111/033518/1&agg=rss Srinivasa Rao Gunti and Sundarrajan Asokan<br/> We have investigated thermal properties of bulk SiTeAg (4 <= x <= 20) glasses in detail, through alternating differential scanning calorimetry experiments. The composition dependence of thermal parameters reveal the signatures of rigidity percolation and chemical threshold at compositions x = 12 and ... [J. Appl. Phys. 111, 033518 (2012)] published Wed Feb 8, 2012. Identifying and evaluating organic nonlinear optical materials via molecular moments http://link.aip.org/link/?JAP/111/033512/1&agg=rss A. P. Higginbotham, J. M. Cole, M. A. Blood-Forsythe, and D. D. Hickstein<br/> We demonstrate how to appropriately estimate the zero-frequency (static) hyperpolarizability of an organic molecule from its charge distribution, and we explore applications of these estimates for identifying and evaluating new organic nonlinear optical (NLO) materials. First, we calculate hyperpola ... [J. Appl. Phys. 111, 033512 (2012)] published Tue Feb 7, 2012. The effect of In-flush on the optical anisotropy of InAs/GaAs quantum dots http://link.aip.org/link/?JAP/111/033510/1&agg=rss M. Molas, K. Golasa, K. Kuldova, J. Borysiuk, A. Babinski et al.<br/> The effect of the In-flush technique on the optical anisotropy of InAs/GaAs quantum dots (QDs) has been investigated. The anisotropy was deduced from low temperature microluminescence measurements of the splitting of the emission lines related to single neutral excitons confined to the QDs. It was f ... [J. Appl. Phys. 111, 033510 (2012)] published Mon Feb 6, 2012. Interfaces between nonpolar and semipolar III-nitride semiconductor orientations: Structure and defects http://link.aip.org/link/?JAP/111/033507/1&agg=rss J. Kioseoglou, A. Lotsari, E. Kalesaki, and G. P. Dimitrakopulos<br/> Observations of easy transition between nonpolar and semipolar orientations during III-Nitride heteroepitaxy identify the 90 <[overline 1]2[overline 1]0> rotation relationship as being very important in defining this coexistence. A rigorous analysis of this relationship using the topological theory ... [J. Appl. Phys. 111, 033507 (2012)] published Mon Feb 6, 2012. In situ crystallization kinetics studies of plasma-deposited, hydrogenated amorphous silicon layers http://link.aip.org/link/?JAP/111/033508/1&agg=rss K. Sharma, M. A. Verheijen, M. C. M. van de Sanden, and M. Creatore<br/> The impact of the amorphous silicon properties, i.e., the microstructure parameter R* and the medium range order (MRO), on the crystallization process is highlighted and discussed. In agreement with literature, the development of large grains extending through the thickness of the poly-Si layer is f ... [J. Appl. Phys. 111, 033508 (2012)] published Mon Feb 6, 2012. The study of pressure induced structural phase transition in spin-frustrated YbTiO pyrochlore http://link.aip.org/link/?JAP/111/033509/1&agg=rss A. K. Mishra, H. K. Poswal, Surinder M. Sharma, Surajit Saha, D. V. S. Muthu et al.<br/> Our in situ x-ray diffraction and Raman measurements of YbTiO pyrochlore show that it undergoes a reversible structural phase transition from cubic pyrochlore to a monoclinic phase at ~28.6 GPa. Analysis of the x-ray data shows the transition to be thermodynamically first order and the high pressure ... [J. Appl. Phys. 111, 033509 (2012)] published Mon Feb 6, 2012. Sound velocity measurements of tantalum under shock compression in the 10-110 GPa range http://link.aip.org/link/?JAP/111/033511/1&agg=rss Jianbo Hu, Chengda Dai, Yuying Yu, Zijiang Liu, Ye Tan et al.<br/> The high-pressure melting curve of tantalum (Ta) has been the center of a long-standing controversy. Sound velocities along the Hugoniot curve are expected to help in understanding this issue. To that end, we employed a direct-reverse impact technique and velocity interferometry to determine sound v ... [J. Appl. Phys. 111, 033511 (2012)] published Mon Feb 6, 2012. Characteristics of thickness-shear modes excited by two-layer piezoelectric film in acoustic sensors http://link.aip.org/link/?JAP/111/033504/1&agg=rss Hui Zhang, Shu-yi Zhang, Li Fan, and Yu-ran Wang<br/> The thickness-shear mode (TSM) excited by two-layer, (11[overline 2]0)-textured, hexagonal piezoelectric film is studied to improve the performances of the acoustic sensors. The corresponding theoretical model is presented by the acoustic wave propagation theory in multi-layer structure combined wit ... [J. Appl. Phys. 111, 033504 (2012)] published Fri Feb 3, 2012. Enhanced indirect ferromagnetic p-d exchange coupling of Mn in oxygen rich ZnO:Mn nanoparticles synthesized by wet chemical method http://link.aip.org/link/?JAP/111/033503/1&agg=rss Usman Ilyas, R. S. Rawat, T. L. Tan, P. Lee, R. Chen et al.<br/> This paper investigates the ferromagnetism in ZnO:Mn powders and presents our findings about the role played by the doping concentration and the structural defects towards the ferromagnetic signal. The narrow-size-distributed ZnO:Mn nanoparticles based powders with oxygen rich stoichiometery were sy ... [J. Appl. Phys. 111, 033503 (2012)] published Fri Feb 3, 2012. Dielectric function spectra and critical-point energies of CuZnSnSe from 0.5 to 9.0 eV http://link.aip.org/link/?JAP/111/033506/1&agg=rss S. G. Choi, H. Y. Zhao, C. Persson, C. L. Perkins, A. L. Donohue et al.<br/> We present dielectric function [eh] = [eh] + i[eh] spectra and critical-point energies of CuZnSnSe determined by spectroscopic ellipsometry from 0.5 to 9.0 eV. We reduce artifacts from surface overlayers to the maximum extent possible by performing chemical-mechanical polishing and wet-chemical etch ... [J. Appl. Phys. 111, 033506 (2012)] published Fri Feb 3, 2012. Tuning upconversion emission by controlling particle shape in NaYF:Yb/Er nanocrystals http://link.aip.org/link/?JAP/111/033505/1&agg=rss Dangli Gao, Xiangyu Zhang, and Wei Gao<br/> Rod-shaped and plate-shaped NaYF:Yb/Er nanocrystals (NCs) have been synthesized via a facile oleic acid-assisted hydrothermal route. The intensity and color tunability by shape controlling of NCs is demonstrated by up and down frequency conversions in NaYF:Yb/Er NCs. The results obviously show that ... [J. Appl. Phys. 111, 033505 (2012)] published Fri Feb 3, 2012. Composition dependence of elastic constants in wurtzite AlGaInN alloys http://link.aip.org/link/?JAP/111/033502/1&agg=rss M. Lopuszynski and J. A. Majewski<br/> In this paper, we analyze the dependence of elastic constants c on composition for random wurtzite quaternary AlGaInN alloy in the whole concentration range. The study takes as its starting point the c parameters for zinc blende phase calculated earlier by the authors on the basis of valence force f ... [J. Appl. Phys. 111, 033502 (2012)] published Thu Feb 2, 2012. Oxygen vacancyinduced ferromagnetism in un-doped ZnO thin films http://link.aip.org/link/?JAP/111/033501/1&agg=rss Peng Zhan, Weipeng Wang, Can Liu, Yang Hu, Zhengcao Li et al.<br/> ZnO films became ferromagnetic when defects were introduced by thermal-annealing in flowing argon. This ferromagnetism, as shown by the photoluminescence measurement and positron annihilation analysis, was induced by the singly occupied oxygen vacancy with a saturated magnetization dependent positiv ... [J. Appl. Phys. 111, 033501 (2012)] published Wed Feb 1, 2012. Coupled plastic flow and phase transformation under compression of materials in a diamond anvil cell: Effects of transformation kinetics and yield strength http://link.aip.org/link/?JAP/111/023518/1&agg=rss Oleg M. Zarechnyy, Valery I. Levitas, and Yanzhang Ma<br/> The large-strain problem on phase transformations (PTs) under compression in a diamond anvil cell is studied in detail using the finite-element method. The combined effect of transformation kinetics and ratios of the yield strengths of low- and high-pressure phases is examined. Some experimental phe ... [J. Appl. Phys. 111, 023518 (2012)] published Tue Jan 31, 2012.