UScholar Works
 
Filters: Department: "Materials Science & Engineering" School Or College: "College of Engineering" Collection: "ir_uspace" Format: "application/pdf"
76 - 100 of 275
Number of results to display per page
CreatorTitleDescriptionSubjectDate
76 Liu, FengRole of vacancy on trapping interstitial O in heavily As-doped SiWe have investigated the interstitial oxygen (Oi) diffusion in heavily arsenic (As)-doped Si using first-principles calculations. We show that it is not the As per se but the Si vacancy (V) that trap Oi to reduce its diffusion. Arsenic actually plays the role of an arbitrator to activate thermal ge...Vacancy; Interstitial oxygen; As-doped Si; Arsenic doped silicon; Oxygen trapping; Oxygen diffusion2008
77 Stringfellow, Gerald B.; Williams, Clayton C.Atomic ordering of GaInP studied by Kelvin probe force microscopyThe atomic ordering of GaInP has been established and studied by a variety of methods, including transmission electron microscopy, cathodoluminescence, and photoluminescence. In this work, a Kelvin probe force microscope _x0002_KPFM_x0003_ has been employed to image several GaInP samples previous...Cathodoluminescence; Photoluminescence; Surface morphology1995
78 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
79 Liu, FengSelf-organized replication of 3D coherent island size and shape in multilayer heteroepitaxial filmsA model is proposed to elucidate the evolution of the morphology of strained 3D islands in multilayer heteroepitaxial films. The model explains the experimental observation that islands grown in successive layers not only replicate, forming individual island columns, but self-organize to reach a com...Coherent island size; Island shape; Heteroepitaxial films; Strained 3D islands; Heteroepitaxial films1999-03
80 Stringfellow, Gerald B.Use of Nitrogen to disorder GaInPSignificant changes in microstructure, surface structure, and alloy composition have been observed in GaInP with the addition of nitrogen. These effects occur due to surface changes induced by small concentrations of nitrogen. Transmission electron microscopy and photoluminescence experiments indica...Nitrogen; Alloys; Transmission2004
81 Stringfellow, Gerald B.Organometallic vapor phase epitaxial growth of AlGaInPAlx Ga,, In, _ x _ y P with x + y = 0.51, lattice matched to the GaAs substrate, has been grown by organometaUic vapor phase epitaxy. The simple, horizontal, IR heated system operates at atmospheric pressure using the reactants TMA1, TMGa, TMln, PH3, and K2. Alloys giving room temperature, band edge...Liquid phase epitaxial growth; LPE; Alloys; Surface morphology1985
82 Stringfellow, Gerald B.Step structure and ordering in GaInPPresents information from an experiment on the step structure and ordering in GalnP. Information on the step spacing and degree of order in the epitaxial layers; Details on the experiment; Results from the experiment.Physics; Ordering; Steps1998
83 Stringfellow, Gerald B.Radiative pair transitions in p-type ZnSe:Cu crystalsShallow levels with an ionization energy of 0.012 eV play an important role in the photoelectronic properties of p-type ZnSe:Cu crystals. These levels exhibit the characteristics of the higher-lying member of an imperfection pair involved in luminescence emission, as well as of a trap determining lo...Ionization energy; Luminescence emission; Crystals1968
84 Bedrov, Dmitro; Smith, Grant D.Temperature dependent shear viscosity coefficient of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX ): a molecular dynamics simulation studyEquilibrium molecular dynamics methods were used in conjunction with linear response theory and a recently published potential-energy surface [J. Phys. Chem. B 103, 3570 (1999)] to compute the liquid shear viscosity and self-diffusion coefficient of the high explosive HMX (octahydro-1,3,5,7-tetran...Polymer melts; HMX; Shear viscosity coefficient; Plastic-bonded explosives2000
85 Liu, FengSelf-organization of semiconductor nanocrystals by selective surface facetingThe formation and ordering of Si nanocrystals in dewetting and agglomeration of the thin single crystalline Si layer in silicon-on-insulator has been investigated using low-energy electron microscopy. The evolution of the Si dewetting and agglomeration is captured in real time, revealing the detai...Self-organization; Surface faceting; Silicon nanocrystals; Dewetting2005-12
86 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
87 Stringfellow, Gerald B.Control of ordering in Ga0.5In0.5P using growth temperatureThe kinetic processes leading to ordering in Gas,, In o.4P8 have been studied by observing the effects of substrate misorientation (O-9), growth rate (0.1-0.5), and substrate temperature (570- 670 "C) during growth. The ordered structure and degree of ordering are determined using transmission elec...Ordering Structure; Growth Temprature; Growth Rate1994
88 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
89 Scarpulla, MichaelSynthesis and properties of highly mismatched II-O-I alloysTernary and quaternary dilute II-VI oxides were synthesised using a highly nonequilibrium method: the combination of O ion implantation and pulsed-laser melting. CdOxTe12x thin films have been produced with x up to 0.015 and with the energy gap reduced by 0.15 eV. Optical transitions corresponding t...Highly mismatched alloys; Cadmium telluride; Zinc telluride; Anticrossing2004
90 Liu, FengSelf-assembly of three-dimensional metal islands: nonstrained versus strained islandsA theoretical model for the Volmer-Weber growth of three-dimensional metal islands is proposed, with a dipolar island edge-edge interaction. The existence of such an island edge effect makes the island shape dependent on island size. Furthermore, it induces a stable island size against coarsening, l...Self-assembly; Three dimensional islands; Metal islands; Nonstrained islands; Strained islands; Volmer-Weber growth2002-11
91 Liu, FengTheory of equilibrium shape of an anisotropically strained island: thermodynamic limits for growth of nanowiresUsing continuum elastic theory, we show that strain anisotropy removes the shape instability existing for an isotropically strained island. An anistropically strained island has always an anisotropic shape, elongating along the less-strained direction and adopting a narrow width in the more-strain...Strained islands; Equilibrium shape; Growth; Thermodynamic limits2004-11
92 Scarpulla, MichaelGa1-xMnxP synthesized by ion implantation and pulsed-laser meltingThe synthesis of single-crystalline epitaxial thin films of the carrier-mediated ferromagnetic phase of Ga1-xMnxP and Ga1-xMnxP-based quaternary alloys using ion implantation and pulsed-laser melting (II-PLM) has allowed for the exploration of the effect of anion substitution on ferromagnetism in Ga...2008
93 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
94 Tiwari, AshutoshStress-induced tuning of metal-insulator transition in NdNiO3 filmsWe have used the lattice-mismatch epitaxial strain, induced by the constraint of epitaxy, to tune the metal-insulator (M- I) transition temperature of NdNiO3 films grown on Si(100) substrate. Films were integrated with the Si(100) substrate using several combinations of thin buffer layers. A system...NdNiO3; Silicon substrate; Tantalum nitride; Buffer layers; Biaxial strain2002
95 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
96 Stringfellow, Gerald B.Deep electron traps in organometallic vapor phase grown AlGaAsDeep electron traps have been studied by means of deep level transient spectrosocopy in type nominally undoped and interntionally te doped Al Ga As epitaxial layers which were grown by vapor phase epitaxy from organometallic compounds (OMVPE). Three main deep electron levels are present in undoped m...Vapor phase epitaxy; Shallow impurity identity; Optoelectronic device performance1980
97 Scarpulla, MichaelExact field solution to guided wave progagation in lossy thin filmsWave guidance is an important aspect of light trapping in thin film photovoltaics making it important to properly model the effects of loss on the field profiles. This paper derives the full-field solution for electromagnetic wave propagation in a symmetric dielectric slab with finite absorption. ...2011
98 Chaudhuri, Reaz A.On three-dimensional singular stress/residual stress fields at the front of a crack/anticrack in an orthotropic/orthorhombic plate under anti-plane shear loadingA novel eigenfunction expansion technique, based in part on separation of the thickness-variable, is developed to derive three-dimensional asymptotic stress field in the vicinity of the front of a semi-infinite through-thickness crack/anticrack weakening/reinforcing an infinite orthotropic/orthorhom...2010-07
99 Stringfellow, Gerald B.Kinetics of Te doping in disordering GaInP grown by organometallic vapor phase epitaxyTe-doped GaInP epitaxial layers were grown by organometallic vapor phase epitaxy in an effort to clarify the Te disordering mechanism. CuPt ordered GaInP is produced under normal growth conditions. The addition of Te has been reported to induce disorder. One suggested mechanism for disordering GaInP...Crystal growth; Epitaxy; Dynamics2001
100 Liu, FengFirst-principles study of crystalline silicaWe have investigated the structural properties of five different crystalline forms of Si02 using a first-principles approach. An ultrasoft Vanderbilt pseudopotential is generated for oxygen which enables us to use a small plane-wave cutoff of 25 Ry. The relative stability, the equation of state, an...First-principles; Crystalline silica; Ultrasoft Vanderbilt pseudopotential1994-05
76 - 100 of 275