Filters: Department: "Materials Science & Engineering" School Or College: "College of Engineering" Collection: "ir_uspace" Format: "application/pdf"
| Creator | Title | Description | Subject | Date | ||
|---|---|---|---|---|---|---|
| 176 |
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Shetty, Dinesh K. | On the effect of birefringence on light transmission in Polycrystalline Magnesium Fluoride | Light transmission in polycrystalline magnesium fluoride was studied as a function of the mean grain size at different wavelengths. The mean grain size was varied by annealing hot-pressed billets in argon atmosphere at temperatures ranging from 600 to 800°C for 1 hour. The grain-size and grain-orie... | 2014-01-01 | |
| 177 |
 |
Smith, Grant D. | On the non-Gaussianity of chain motion in unentangled polymer melts | We have investigated chain dynamics of an unentangled polybutadiene melt via molecular dynamics simulations and neutron spin echo experiments. Good short-time statistics allows for the first experimental confirmation of subdiffusive motion of polymer chains for times less than the Rouse time (T R) c... | Polymer melts; Chain dynamics; 1,4-polybutadiene melts; Neutron spin echo | 2001 |
| 178 |
 |
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 loading | A 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 | |
| 179 |
 |
Liu, Feng | Orbit- and atom-resolved spin textures of intrinsic, extrinsic, and hybridized Dirac cone states | Combining first-principles calculations and spin- and angle-resolved photoemission spectroscopy measurements, we identify the helical spin textures for three different Dirac cone states in the interfaced systems of a two-dimensional (2D) topological insulator (TI) of a Bi(111) bilayer and a three-di... | 2014-01-01 | |
| 180 |
 |
Stringfellow, Gerald B. | Organometallic vapor phase epitaxial growth of AlGaInP | Alx 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 morphology | 1985 |
| 181 |
 |
Stringfellow, Gerald B.; Cohen, Richard M. | Organometallic vapor phase epitaxial growth of high purity GaInAs using trimethylindium | Gax In1−xAs lattice matched to the InP substrate (x=0.47) has been grown by organometallic vapor phase epitaxy using trimethylindium (TMIn) and trimethylgallium (TMGa) as the group III sources and AsH3 as the As source. In a simple, horizontal, atmospheric pressure reactor, the GaInAs growth proce... | Electron mobilities; Photouminescience; Fabricate modulation | 1984-03-01 |
| 182 |
 |
Liu, Feng | Origin of intergranular embrittlement of Al alloys induced by Na and Ca segregation: grain boundary weakening | Using a first-principles computational tensile test, we show that the ideal tensile strength of an Al grain boundary (GB) is reduced with both Na and Ca GB segregation. We demonstrate that the fracture occurs in the GB interface, dominated by the break of the interfacial bonds. Experimentally, we f... | Intergranular embrittlement; Grain boundary; Intergranular fracture | 2006-06 |
| 183 |
 |
Tiwari, Ashutosh | Oxides for spintronics: a review of engineered materials for spin injection | In this article we have reviewed the role of oxides in spintronics research, and specifically how these materials stand to further improve the efficiencies and capabilities of spin injection for active spintronic device development. The use of oxides in spintronics is advantageous in that they are s... | 2014-01-01 | |
| 184 |
 |
Liu, Feng | Pattern formation on silicon-on-insulator | The strain driven self-assembly of faceted Ge nanocrystals during epitaxy on Si(001) to form quantum dots (QDs) is by now well known. We have also recently provided an understanding of the thermodynamic driving force for directed assembly of QDs on bulk Si (extendable to other QD systems) based on ... | Pattern formation; Silicon-on-insulator; Strain driven; Faceted Ge nanocrystals; Si(001); Directed assembly | 2005 |
| 185 |
 |
Liu, Feng | Pattern formation via a two-step faceting transition on vicinal Si(111) surfaces | We demonstrate a self-organized pattern formation on vicinal Si(l 11) surfaces that are miscut toward the [211] direction. All the patterns, consisting of a periodic array of alternating (7x7) reconstructed terraces and step-bunched facets, have the same periodicity and facet structure, independent ... | Pattern formation; Faceting transition; Vicinal Si(111); Miscut | 2001 |
| 186 |
 |
Stringfellow, Gerald B. | Photoluminescence of Shallow Acceptors in Epitaxial AlGaAs | The low-temperature (2 K) photoluminescence (PL) of AlxGa1-xAs (0<x<0.25 was studied in an effort to characterize shallow acceptors in material grown by organometallic vapor phase epitaxy and liquid phase epitaxy techniques. The dominant shallow acceptor in nominally undoped AlxGa1-xAs specimens gro... | Photoluminescence; Acceptors; Doping | 1980 |
| 187 |
 |
Liu, Feng | Physical origin of hydrogen-adsorption-induced metallization of the SiC surface: n-type doping via formation of hydrogen bridge bond | We perform first-principles calculations to explore the physical origin of hydrogen-induced semiconductor surface metallization observed in β-SiC(001)-3 x 2 surface. We show that the surface metallization arises from a novel mechanism of n-type doping of surface band via formation of hydrogen bri... | Metallization; Hydrogen adsorption; SiC; n-type doping; Hydrogen bridge bond | 2005-10 |
| 188 |
 |
Liu, Feng | Prediction of a Dirac state in monolayer TiB2 | We predict the existence of a Dirac state in a monolayer TiB2 sheet (m-TiB2), a two-dimensionalmetal diboride, based on first-principles calculations. The band structure of m-TiB2 is found to be characterized with anisotropic Dirac cones with the largest Fermi velocity of 0.57 × 106 m/s, which is a... | 2014-01-01 | |
| 189 |
 |
Liu, Feng | Pressure-induced hard-to-soft transition of a single carbon nanotube | We demonstrate a hydrostatic pressure-induced hard-to-soft transition of an isolated single wall carbon nanotube, using classical and ab initio constant-pressure molecular-dynamics simulations and continuum elastic theory analysis. At low pressure, the carbon tube is hard. Above a critical pressur... | Carbon nanotubes; Hard-to-soft transition | 2004-10 |
| 190 |
 |
Liu, Feng | Pressure-induced transition in magnetoresistance of single-walled carbon nanotubes | We applied hydrostatic pressure (up to 10 GPa) to single-walled carbon nanotube bundles at low temperature (down to 2 K) to measure their magnetoresistance (MR) in a field up to 12 T. We found a pressure-induced transition in MR from positive to negative in the high-field regime. The onset of the tr... | Single-walled carbon nanotubes; Pressure-induced | 2006-07 |
| 191 |
 |
Scarpulla, Michael | Probing semiconductor band structures and heterojunction interface properties with ballistic carrier emission: GaAs/AlxGa1-xAs as a model system | Utilizing three-terminal tunnel emission of ballistic electrons and holes in a planar tunnel transistor with a Mott-barrier collector, we have developed a method to self-consistently determine the energy gap of a semiconductor and band discontinuities at a semiconductor heterojunction without using... | 2010-06 | |
| 192 |
 |
Scarpulla, Michael | Pulsed and continuous wave solid phase laser annealing of electrodeposited CuInSe2 thin films | Cu(In,Ga)Se2 (CIGS) thin film photovoltaic absorber layers are primarily synthesized by vacuum based techniques at industrial scale. In this work, we investigate non-vacuum film synthesis by electrochemical deposition coupled with pulsed laser annealing (PLA) and or continuous wave laser annealing (... | 2012-01-01 | |
| 193 |
 |
Tiwari, Ashutosh | Pulsed laser deposition and characterization of Zn1-xMnxO films | Here we present our results of structural, optical, and magnetic measurements of Zn1-xMnxO thin films. These films were grown epitaxially on (0001) sapphire substrates by using pulsed laser deposition technique. The maximum Mn content (x=0.36) is found to be much higher than allowed by thermal equl... | 2002 | |
| 194 |
 |
Scarpulla, Michael | Pulsed laser induced ohmic back contact in CdTe solar cells | Creating an ohmic back contact has long been a problem for making efficient CdTe solar cells. Current devices utilize some combination of preferential chemical etching, buffer layer, and Cu doping with additional cost, time, and complexity added for each step. In this Letter, these processes are esc... | 2014-01-01 | |
| 195 |
 |
Scarpulla, Michael | Pulsed laser processing of electrodeposited CuInSe2 photovoltaic absorber thin films | In this report we investigate the effects of pulsed laser annealing (PLA) on both as-electrodeposited (ED) and electrodeposited-furnace annealed (EDA) CuInSe2 (CIS) samples by varying the laser fluence (J/cm2) and number of pulses. Results for as-ED samples indicate that liquid CIS-phase formation d... | 2011-01-01 | |
| 196 |
 |
Liu, Feng | Quantum size effect on adatom surface diffusion | Using scanning tunneling microscopy, we demonstrate that the nucleation density of Fe islands on the surface of nanoscale Pb films oscillates with the film thickness, providing a direct manifestation of the quantum size effect on surface diffusion. The Fe adatom diffusion barriers were derived to be... | Quantum size effect; QSE; Adatoms; Surface diffusion; Fe islands; Nanoscale metallic structures; Epitaxial growth; Pb films | 2006-12 |
| 197 |
 |
Liu, Feng | Quantum size effect on the magnetism of finite systems | The magnetic moments of the ferromagnetic transition metals Fe, Co, and Ni confined to one-dimensional chains are found to fluctuate with increasing chain length before converging to the infinite limit. This quantum size effect is derived from a simple first-principles theory that we have developed... | Quantum size; Finite systems; Ferromagnetic transition metals; Magnetic moments; Fe; Co; Ni; Molecular-orbital approach | 1990-07 |
| 198 |
 |
Stringfellow, Gerald B.; Inglefield, Colin E.; Taylor, P. Craig | Quantum wells due to ordering in GaInP | CuPt ordering results in a reduction of the band-gap energy of GaInP. Thus, heterostructures and quantum wells can be produced by simply varying the order parameter, without changing the solid composition. Changes in the order parameter can be induced by changes in growth conditions. The disorder... | Band-gap energy; Growth temperature; Quantum wells | 1998-12-28 |
| 199 |
 |
Stringfellow, Gerald B. | Radiative pair transitions in p-type ZnSe:Cu crystals | Shallow 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; Crystals | 1968 |
| 200 |
 |
Tiwari, Ashutosh | Rectifying electrical characteristics of La0.7Sr0.3MnO3/Zno heterostructure | We have fabricated a p - n junction, consisting of p-type manganite (La0.7Sr0.3MnO3) and n-type ZnO layers grown on sapphire substrate. This junction exhibits excellent rectifying behavior over the temperature range 20-300 K. Electrical characteristics of La0.7Sr0.3MnO3 (LSMO) film in this heterostr... | Manganites | 2003 |