Filters: Department: "Materials Science & Engineering" Collection: "ir_uspace" Format: "application/pdf"
| Creator | Title | Description | Subject | Date | ||
|---|---|---|---|---|---|---|
| 226 |
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Liu, Feng | Thermal roughening of a thin film: a new type of roughening transition | The equilibrium thermal roughening of thin Ge layers (one and two monolayers) deposited on Si(001) has been investigated with low-energy electron microscopy. A Ge-coverage-dependent roughening is observed. For two monolayers, the temperature at which imaging contrast is lost due to surface roughness... | Thermal roughening; Roughening transition; Heteroepitaxial growth | 2000-09 |
| 227 |
 |
Liu, Feng | Enhanced growth instability of a strained film on wavy substrate | We demonstrate that the growth of a strained film is inherently less stable on a wavy substrate than on a flat substrate. For small surface undulation, the lowest strain energy state is for the film surface to adopt the same wavelength as the substrate surface in an antiphase configuration at the ea... | Growth instability; Strained film; Wavy substrate; Strain induced self-assembly | 2008 |
| 228 |
 |
Stringfellow, Gerald B. | Te doping of GaInP: ordering and step structure | The donor Te has been added to GaInP during organometallic vapor phase epitaxial growth using the precursor diethyltelluride. In agreement with previous studies, the addition of high Te concentrations leads to the elimination of the CuPt ordering observed in undoped layers. The degree of order is es... | Epitaxial growth; Heterostructures; Growth parameters | 1999-04-01 |
| 229 |
 |
Scarpulla, Michael | Effect of film thickness on the incorporation of Mn interstitials in Ga1-xMnxAs | We have investigated the effect of film thickness on the distribution of Mn atoms at various lattice sites in Ga1−xMnxAs thin films. We find that the growth surface acts as a sink facilitating the outdiffusion of Mn interstitials sMnId, and thus reducing its concentration in the film. The outdiffu... | Interstitials; Gallium arsenide | 2005 |
| 230 |
 |
Stringfellow, Gerald B. | Surface photoabsorption study of the effect of substrate misorientation on ordering in GaInP | Substrate orientation strongly affects Cu-Pt ordering in Ga0.5In0.5P layers grown by organometallic vapor phase epitaxy. In situ surface photoabsorption SPA measurements were used to measure the concentration of 1 10-oriented P dimers, characteristic of the 2 4 reconstructed surface, as a functio... | P-dimer concentration; Photoluminescence measurements; Surface reconstruction | 1996-04-15 |
| 231 |
 |
Stringfellow, Gerald B. | GaInAsSb metastable alloys grown by organometallic vapor phase epitaxy | Ga1-xlnx As1-ySby alloys have been grown by organometallic vapor phase epitaxy using trimethyl compounds of Ga, In, As, and Sb(TMGa, TMIn, TMAs, and TMSb) plus AsH3 in an atmospheric pressure, horizontal, infrared heated reactor. For the first time, alloys near the center of the region of solid immi... | Organometallic; Alloys; Vapor phase epitaxy | 1986 |
| 232 |
 |
Liu, Feng | Magnetization on vicinal ferromagnetic surfaces | Using Ising model Monte Carlo simulations, we show a strong dependence of surface magnetization on surface miscut angle. For ferromagnetic surfaces, when surface spin exchange coupling is larger than that of the bulk, the surface magnetic ordering temperature decreases, toward the bulk Curie tempera... | Vicinal ferromagnetic surfaces; Surface magnetization; Surface miscut angle | 1997 |
| 233 |
 |
Scarpulla, Michael | Heat flow model for pulsed laser melting and rapid solidification of ion implanted GaAs | In order to further understand the pulsed-laser melting (PLM) of Mn and N implanted GaAs, which we have used to synthesize thin films of the ferromagnetic semiconductor Ga1−xMnxAs and the highly mismatched alloy GaNxAs1−x, we have simulated PLM of amorphous (a-) and crystalline (c-) GaAs. We pre... | 2010 | |
| 234 |
 |
Stringfellow, Gerald B. | Tertiarybutyldimethylantimony: a new Sb source for low temperature organometallic vapor phase epitaxial growth of InSb | This article investigates tertiarybutyldimethylantimony as a source for low-temperature organometallic vapor phase epitaxial growth of indium antimonide (InSB); extraction of good surface morphology InSb layers; efficiency of InSB growth; and, presence of a negligible parasitic reaction between trim... | Tertiarybutyldimethylantimony; Indium antimonide crystals | 1992 |
| 235 |
 |
Scarpulla, Michael | Determination of the infrared complex magnetoconductivity tensor in itinerant ferromagnets from Faraday and Kerr measurements | We present measurement and analysis techniques that allow the complete complex magnetoconductivity tensor to be determined from midinfrared (11-1.6 μm; 100-800 meV) measurements of the complex Faraday (θF) and Kerr (θK) angles. Since this approach involves measurement of the geometry (orientati... | Magnetoconductivity tensor; Ferromagnets | 2007-06 |
| 236 |
 |
Scarpulla, Michael | Ferromagnetic resonance investigation of magnetic anisotropy in Ga1-xMnxAs synthesized by ion implantation and pulsed laser melting | A systematic investigation of ferromagnetic resonance (FMR) was carried out on Ga1−xMnxAs layers synthesized by Mn ion implantation into GaAs followed by pulsed laser melting. Angular and temperature dependences of FMR were measured on layers prepared on GaAs (001), (110), and (311) surfaces. The ... | Magnetic anisotropy; Ga1−xMnxAs; Gallium manganese arsenide | 2009-12 |
| 237 |
 |
Stringfellow, Gerald B. | Doping studies of Ga0.5In0.5P organometallic vapor-phase epitaxy | Presents doping studies of gallium[sub0.5] indium[sub0.5] phosphorus organometallic vapor-phase epitaxy. Distribution coefficient of indium; Description of growth conditions; Case of poor growth morphology for gallium[sub0.5] indium[sub0.5] phosphorus. | Phosphorus; Gallium; Doping | 1986 |
| 238 |
 |
Scarpulla, Michael | Carrier concentration dependencies of magnetization & transport in Ga1-xMnxAs1-yTey | We have investigated the transport and magnetization characteristics of Ga1-xMnxAs intentionally compensated with shallow Te donors. Using ion implantation followed by pulsed-laser melting, we vary the Te compensation and drive the system through a metal-insulator transition (MIT). This MIT is assoc... | Gallium arsenide; Ferromagnetic semiconductors; Magnetization; Resistivity | 2005 |
| 239 |
 |
Liu, Feng | Strain-engineered surface transport in Si(001): complete isolation of the surface state via tensile strain | By combining density functional theory, nonequilibrium Green's function formulism and effective- Hamiltonian approaches, we demonstrate strain-engineered surface transport in Si(001), with the complete isolation of the Si surface states from the bulk bands. Our results show that sufficient tensile s... | 2013-01-01 | |
| 240 |
 |
Scarpulla, Michael | Surface stoichiometry of pulsed ultraviolet laser treated polycrystalline CdTe | The effects of nanosecond pulsed ultraviolet laser annealing on the surface stoichiometry of close-space sublimated polycrystalline thin films are investigated using angle-resolved x-ray photoemission spectroscopy (XPS). The raw data suggest the formation of a Cd-rich surface layer, but this is coun... | 2014-01-01 | |
| 241 |
 |
Scarpulla, Michael | Te-rich CdTe surface by pulsed UV laser treatment for ohmic back contact formation | Pulsed UV laser treatments have recently been applied to polycrystalline CdTe solar cells to create an ohmic back contact. In this work, we investigate the surface stoichiometry variations produced by pulsed laser excitation using X-ray photoelectron spectroscopy (XPS). These results reveal surfaces... | 2014-01-01 | |
| 242 |
 |
Tiwari, Ashutosh | Tb2O3 thin films: An alternative candidate for high-k dielectric applications | We are reporting the growth and structural, optical, and dielectric properties of Tb2O3, a relatively unexplored high-k dielectric material. A pulsed-laser deposition technique was used to grow Tb2O3 thin-films on four different substrates: Si(100), SrTiO3(100), LaAlO3(100), and MgO(100). High resol... | 2014-01-01 | |
| 243 |
 |
Tiwari, Ashutosh | Mid- to long-wavelength infrared surface plasmon properties in doped zinc oxides | This 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 | |
| 244 |
 |
Tiwari, Ashutosh | Modification of high potential, high capacity Li2FeP 2O7 cathode material for lithium ion batteries | Li2FeP2O7 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 | |
| 245 |
 |
Tiwari, Ashutosh | Observation of the inverse spin hall effect in ZnO thin films: an all-electrical approach to spin injection and detection | The 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 | |
| 246 |
 |
Liu, Feng | Impurity mediated absorption continuum in single-walled carbon nanotubes | The authors demonstrate that in single-walled carbon nanotubes, a weak impurity potential can lead to a strong above-gap absorption continuum. The total absorption is enhanced due to the intraband and indirect transitions, as well as plasmon excitations, which are forbidden in perfect nanotubes. Suc... | Carbon nanotubes; SWNT; Defects; Impurities; Above-gap; Absorption continuum | 2007 |
| 247 |
 |
Liu, Feng | Critical epinucleation on reconstructured surfaces and first-principle calculation of homonucleation on Si(100) | We introduce the concept of ‘‘critical epinucleation'' to distinguish nucleation on surfaces with and without reconstruction. On a reconstructed surface, the critical classical nucleus is stable against dissociation, but may not yet break the underlying surface reconstruction. Consequently, ther... | Critical epinucleation; First-principle calculation; Homonucleation; Si(100); Islands | 2005-09 |
| 248 |
 |
Tiwari, Ashutosh | Experiments along coexistence near tricriticality in 3He-4He mixtures | The tricritical point in the phase diagram of 3He-4He mixtures offers unique opportunities to test our understanding of critical phenomena. Because D = 3 is the marginal spatial dimension for tricriticality, the associated critical exponents are exact integer fractions. In addition, one expects to f... | Tricriticality; Tricritical point; 3He-4He mixtures | 2000 |
| 249 |
 |
Stringfellow, Gerald B.; Shurtleff, James Kevin | Surfactant effects on doping of GaAs grown by organometallic vapor phase epitaxy | Recently, the addition of the isoelectronic surfactant Sb during organometallic vapor phase epitaxy (OMVPE) of GaInP was shown to eliminate ordering, resulting in a significant change in the band gap energy. These results suggest that surfactants added during growth could have profound affects on ot... | Gallium arsenide; Surfactants; Semiconductors | 2001 |
| 250 |
 |
Stringfellow, Gerald B. | Effects of substrate misorientation and growth rate on ordering in GaInP | Epitaxial layers of Ga,Tn,_,P with 1=0.52 have been grown by-organometallic vapor-phase apitaxy on GaAs substrates misoriented from the (001) plane in the [ 1 IO] direction by angles 6,) of O", 3", 6", and 9". For each substrate orientation growth rates rg of 1, 2, and 4 pm/h have been used. The ... | Transmission electron diffraction; Dark-field imaging; Photoluminescence | 1994 |