UScholar Works
 
Filters: Department: "Materials Science & Engineering" School Or College: "College of Engineering" Collection: "ir_uspace" Format: "application/pdf"
151 - 175 of 275
Number of results to display per page
CreatorTitleDescriptionSubjectDate
151 Tiwari, AshutoshMetallic conductivity and metal-semiconductor transition in Ga-doped ZnOThis letter reports the metallic conductivity in Ga:ZnO system at room temperature and a metal-semiconductor transition (MST) behavior at low temperatures. Zn0.95Ga0.05O films, deposited by pulsed laser deposition in the pressure range of ~10−2 Torr of oxygen, were found to be crystalline and exhi...Transparent conducting oxides; ZnO; Gallium; Metallic conductivity2006
152 Tiwari, AshutoshMethods of forming three-dimensional nanodot arrays in a matrixNanostructures and methods of making nanostructures having self-assembled nanodot arrays wherein nanodots are self-assembled in a matrix material due to the free energies of the nanodot material and/or differences in the Gibb's free energy of the nanodot materials and matrix materials.Nanodots2006
153 Tiwari, AshutoshMid- to long-wavelength infrared surface plasmon properties in doped zinc oxidesThis work investigates properties of surface plasmons on doped metal oxides in the 2-20 μm wavelength regime. By varying the stoichiometry in pulse laser deposited Ga and Al doped ZnO, the plasmonic properties can be controlled via a fluctuating free carrier concentration. This deterministic approa...2012-01-01
154 Stringfellow, Gerald B.Miscibility gaps and spinodal decomposition in III/V quaternary alloys of the type AxByC1−x−yDThermodynamic concepts have been developed for the calculation of solid-phase miscibility gaps and spinodal decomposition in quaternary alloys of the type AxByC1−x−yD. These concepts have been applied to the analysis of III/V quaternary alloys using the delta-lattice-parameter (DLP) solution mod...Thermodynamics; Quartenary alloys; Coherent decomposition1983-01
155 Scarpulla, MichaelMn L3,2 x-ray absorption and magnetic circular dichroism in ferromagnetic Ga1-xMnxPWe have measured the x-ray absorption and x-ray magnetic circular dichroism (XMCD) at the Mn L3,2 edges in ferromagnetic Ga1−xMnxP films for 0.018≤x≤0.042. Large XMCD asymmetries at the L3 edge indicate significant spin polarization of the density of states at the Fermi energy. The temperatur...X-ray absorption; Gallium Arsenide; Ferromagnetic semiconductors2006
156 Scarpulla, MichaelMn L3,2 x-ray absorption spectroscopy and magnetic circular dichroism in ferromagnetic Ga1-xMnxPWe have measured the X-ray absorption (XAS) and X-ray magnetic circular dichroism (XMCD) at the Mn i32 edges in ferromagnetic Ga1-xMrixP films for 0.018<x<0.042. Large XMCD asymmetries at the L3 edge indicate significant spin-polarization of the density of states at the Fermi energy. The spectral s...X-ray absorption; Ferromagnetic semiconductors; X-ray magnetic circular dichroism (XMCD); Gallium Manganese Phosphide; Gallium arsenide2007
157 Liu, FengModification of Si(001) substrate bonding by adsorbed Ge or Si dimer islandsHigh-resolution scanning tunneling microscopy studies of the Si(100)-(2 X 1) surface show a heretofore unrecognized distortion of the substrate structure when islands form during the initial stage of growth of either Si or Ge. The distortion, reflecting the influence of strain, extends at least thre...Si(001); Adsorbed Ge; Adsorbed Si; Dimer islands; Substrate bonding; Distortion1998-09
158 Tiwari, AshutoshModification of high potential, high capacity Li2FeP 2O7 cathode material for lithium ion batteriesLi2FeP2O7 is a newly developed polyanionic cathode material for high performance lithium ion batteries. It is considered very attractive due to its large specific capacity, good thermal and chemical stability, and environmental benignity. However, the application of Li2FeP2O7 is limited by its low i...2012-01-01
159 Liu, FengModified Timoshenko formula for bending of ultrathin strained bilayer filmsMechanical bending of nanoscale thin films can be quite different from that of macroscopic thick films. However, current understanding of mechanical bending of nanoscale thin strained bilayer films is often limited within the Timoshenko model [Timoshenko, J. Opt. Soc. Am. 11, 233 (1925)], which was ...Timoshenko formula; Bending theory; Ultrathin films; Strained nanoscale thin films; Nanofilms2008
160 Smith, Grant D.Molecular dynamics simulation studies of the influence of imidazolium structure on the properties of imidazolium/azide ionic liquidsAtomistic molecular dynamics simulations were performed on 1-butyl-3-methyl-imidazolium azide [bmim][N3], 1-butyl-2,3-dimethylimidazolium azide [bmmim][N3], and 1-butynyl-3-methylimidazolium azide [bumim][N3] ionic liquids. The many-body polarizable APPLE&P force field was augmented with parameters ...2012-01-01
161 Bedrov, Dmitro; Smith, Grant D.Molecular dynamics simulation study of elastic properties of HMXAtomistic simulations were used to calculate the isothermal elastic properties for b-, a-, and d-octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). The room-temperature isotherm for each polymorph was computed in the pressure interval 0≤p≤10.6 GPa and was used to extract the initial isot...HMX; Elastic tensors; Isotropic moduli; Polymorphs; Isothermal compression; Lattice parameters2003
162 Bedrov, DmitroMolecular dynamics simulation study of the pressure-volume-temperature behavior of polymers under high pressureIsothermal compression of poly (dimethylsiloxane), 1,4-poly(butadiene), and a model Estane® (in both pure form and a nitroplasticized composition similar to PBX-9501 binder) at pressures up to 100 kbars has been studied using atomistic molecular dynamics (MD) simulations. Comparison of predicted co...2009
163 Bedrov, Dmitro; Smith, Grant D.Molecular dynamics simulations of HMX crystal polymorphs using a flexible molecule force fieldMolecular dynamics simulations using a recently developed quantum chemistry-based atomistic force field [J. Phys. Chem. B 103 (1999) 3570] were performed in order to obtain unit cell parameters, coefficients of thermal expansion, and heats of sublimation for the three pure crystal polymorphs of octa...HMX; Crystal polymorphs; Force field; Coefficients of thermal expansion; Heat of sublimation; Cell parameters2002
164 Smith, Grant D.; Borodin, OlegMolecular-dynamics simulation study of dielectric relaxation in a 1,4-polybutadiene meltWe have carried out atomistic molecular dynamics simulations of a melt of 1,4-poly(butadiene) from temperatures well above the experimentally observed merging of the primary a process and secondary b process down to temperatures approaching the experimentally observed bifurcation temperature. The re...Polymer melts; 1,4-polybutadiene; Chain dynamics; Conformational dynamics2002
165 Ostafin, AgnesMonitoring the synthesis and composition analysis of microsilica encapsulated acetylacetonatocarbonyl triphenylphosphinerhodium catalyst by inductively coupled plasma (ICP) techniquesAbstract-A novel technique to monitor the synthesis process of encapsulated acetylacetonatocarbonyl triphenylphosphinerhodium within a microsilica nanoshell has been studied using inductively coupled plasma (ICP) techniques. Nanospheres sized around 50-100 nm were obtained and ICP was used to quanti...2006
166 Scarpulla, MichaelMutual passivation of group IV donors and nitrogen in diluted GaNxAs1 x alloysWe demonstrate the mutual passivation phenomenon of Ge donors and isovalent N in highly mismatched alloy GaNxAs1-x doped with Ge. Layers of this alloy were formed by the sequential implantation of Ge and N ions followed by pulsed laser melting and rapid thermal annealing. The mutual passivation effe...Highly mismatched alloys; Passivation; Gallium arsenide2003
167 Ostafin, AgnesNanomedicine making headway across the blood brain barrierNanotechnological advances implemented by nanomedicine have allowed significant development of imaging strategies, therapeutics and theranostics for many severe and life threatening diseases such as brain tumors, Alzheimer's disease, Parkinson's disease and other neurological disorders. The Blood-Br...2012-01-01
168 Liu, FengNanostressors and the nanomechanical response of a thin silicon film on an insulatorPseudomorphic three-dimensional Ge nanocrystals (quantum dots) grown on thin silicon-on-insulator substrates can induce significant bending of the silicon template layer that is local on the nanometer scale. We use molecular dynamics simulations and analytical models to confirm the local bending of...Nanostressors; Nanomechanical response; Thin silicon film2002-09
169 Tiwari, AshutoshNanostructured DLC-Ag composites for biomedical applicationsWe have synthesized novel diamondlike carbon coatings with silver nanoparticles embedded into the DLC film. The size of silver nanoparticles that are confined into layered structures has been varied from 5 nm to 50 nm using an ingenious pulsed laser deposition technique. The size of nanoparticles wa...Diamondlike carbon coatings; Nanocrystals2003
170 Liu, FengNature of reactive O2 and slow CO2 evolution kinetics in CO oxidation by TiO2 supported Au clusterRecent experiments on CO oxidation reaction using seven-atom Au clusters deposited on TiO2 surface correlate CO2 formation with oxygen associated with Au clusters. We perform first principles calculations using a seven-atom Au cluster supported on a reduced TiO2 surface to explore potential candidat...Au clusters; TiO2; Kinetic evolution2006
171 Scarpulla, MichaelNear-infrared absorption and semimetal-semiconductor transition in 2 nm ErAs nanoparticles embedded in GaAs and AlAsWe report strong near-infrared absorption peaks in epitaxial films of GaAs and AlAs containing approximately 0.5-5% of the semimetal ErAs. The energy of the resonant absorption peak can be changed from 0.62 to 1.0 eV (2.2-1.4 μm) by variation of the ErAs volume fraction and the substrate temperatu...Near-infrared absorption; Semimetal-semiconductor transition; GaAs; AlAs; ErAs; Gallium arsenide; Aluminum arsenide2008
172 Scarpulla, MichaelNew methodologies for measuring film thickness, coverage, and topographyWe describe how the techniques of X-ray reflectivity (XRR), electron spectroscopy for chemical analysis (ESCA), and atomic force microscopy (AFM) can be used to obtain the structural parameters-thickness, coverage, and topography-of thin films used on magnetic recording disks. We focus on ultra-thi...Atomic force microscopy; Electron spectroscopy for chemical analysis; X-ray reflectivity2000-01
173 Stringfellow, Gerald B.Nitrogen surfactant effects in GaInPThe addition of surfactant nitrogen during the growth of GaInP on 001 GaAs substrates produces significant and interesting changes in the optical and morphological properties of GaInP. In particular, multiple peaks are seen in the low temperature photoluminescence (PL) spectra of GaInP/GaInP:N he...Surfactant nitrogen; Microscopy; Crystals2004
174 Scarpulla, MichaelNonmagnetic compensation in ferromagnetic Ga1-xMnxAs and Ga1-xMnxP synthesized by ion implantation and pulsed-laser meltingThe electronic and magnetic effects of intentional compensation with nonmagnetic donors are investigated in the ferromagnetic semiconductors Ga1−xMnxAs and Ga1−xMnxP synthesized using ion implantation and pulsed-laser melting. It is demonstrated that compensation with nonmagnetic donors and MnI ...Ferromagnetic semiconductors2008
175 Tiwari, AshutoshObservation of the inverse spin hall effect in ZnO thin films: an all-electrical approach to spin injection and detectionThe inverse spin Hall effect (ISHE) is a newly discovered, quantum mechanical phenomenon where an applied spin current results in the generation of an electrical voltage in the transverse direction. It is anticipated that the ISHE can provide a more simple way of measuring spin currents in spintroni...2014-01-01
151 - 175 of 275