Filters: Department: "Materials Science & Engineering" Collection: "ir_uspace" Format: "application/pdf"
| Creator | Title | Description | Subject | Date | ||
|---|---|---|---|---|---|---|
| 176 |
 |
Liu, Feng | Effect of size and dimensionality on the magnetic moment of transition metals | The effect of size and dimensionality on the magnetic moments of Fe, Co, and Ni have been studied theoretically by confining the atoms t o various structural forms such as chains,surfaces, and thin films. The size of these systems is controlled by limiting t h e number of atoms. A new first-princip... | Magnetic moment; Dimensionality; Size effects; Fe; Co; Ni | 1990 |
| 177 |
 |
Tiwari, Ashutosh | Nanostructured DLC-Ag composites for biomedical applications | We 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; Nanocrystals | 2003 |
| 178 |
 |
Liu, Feng | Magnetism and local order: ab initio tight-binding theory | The effects of the local environment on the electronic structure and magnetic moments of Fe, Co, and Ni have been studied by confining these atoms to assume various structural forms such as chains, surfaces, layers, and crystals. The coordination number of the atoms can thus be changed over a wide r... | Local order; Ab-initio tight-binding theory; Magnetic moment; Electronic structure; Fe; Co; Ni | 1989-04 |
| 179 |
 |
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 |
| 180 |
 |
Liu, Feng | First-principles study of strain stabilization of Ge(105) facet on Si(001) | Using the first-principles total energy method, we calculate surface energies, surface stresses, and their strain dependence of the Ge-covered Si (001) and (105) surfaces. The surface energy of the Si(105) surface is shown to be higher than that of Si(001), but it can be reduced by the Ge deposition... | First-principles calculation; Strain stabilization; Ge(105); Si(001); Strained thin films; Epitaxial growth | 2005-09 |
| 181 |
 |
Stringfellow, Gerald B. | Solid phase immiscibility in GaInN | The large difference in interatomic spacing between GaN and InN is found to give rise to a solid phase miscibility gap. The temperature dependence of the binodal and spinodal lines in the Ga1xInxN system was calculated using a modified valence-force-field model where the lattice is allowed to relax ... | Interatomic spacing; Valence-force field; epitaxial growth | 1996 |
| 182 |
 |
Liu, Feng | Equilibrium shape of two-dimensional islands under stress | We show that the equilibrium shape anisotropy of two-dimensional islands in heteroepitaxial growth depends on island size, a consequence of the presence of strain. Even in homoepitaxy, in which the island shape has conventionally been equated with the ratio of step energies, a substrate surface str... | Two-dimensional islands; Equilibrium shape; Heteroepitaxial growth; Homoepitaxy | 2000-08 |
| 183 |
 |
Scarpulla, Michael | Effects of pressure on the band structure of highly mismatched Zn1-yMnyOxTe1-x alloys | We report photomodulation spectroscopy measurements of the pressure dependence of the optical transition in Zn12yMnyOxTe1-x alloys that is associated with the lowest Ѓ conduction band (termed E2 subband). The pressure-induced energy shift of the E2 transition is nonlinear and much weaker as compare... | Highly mismatched alloys; Zinc telluride; Anticrossing | 2004 |
| 184 |
 |
Liu, Feng | (BAl12)Cs: a cluster-assembled solid | First-principles calculations on the geometry and stability of AlnBm clusters have been carried out to examine the effect of size, composition, and electronic-shell filling on their relative stability. It is shown that although Al and B are both trivalent, a BAl12 cluster is more stable than an Al1... | First-principles calculations; (BAl12)Cs; Cluster-assembled; AlnBm clusters | 1997-06 |
| 185 |
 |
Tiwari, Ashutosh | Copper diffusion characteristics in single crystal and polycrystalline TaN | TaN has become a very promising diffusion barrier material for Cu interconnections, due to the high thermal stability requirement and thickness limitation for next generation ULSI devices. TaN has a variety of phases and Cu diffusion characteristics vary with different phases and microstructures. We... | Diffusion barriers; Copper diffusion; Tantalum nitride | 2003 |
| 186 |
 |
Liu, Feng | Step-induced optical anisotropy of vicinal Si(001) | It is demonstrated, using reflectance difference spectroscopy, scanning tunneling microscopy, and low-energy electron diffraction, combined with deliberate straining of the surface, that the presence of atomic steps dramatically changes the optical anisotropy of the Si(001) surface. The step-induce... | Step-induced; Optical anisotropy; Vicinal Si(001); Electron diffraction; Atomic steps | 1999-01 |
| 187 |
 |
Stringfellow, Gerald B. | Effects of surfactants Sb and Bi on the incorporation of zinc and carbon in III/V materials grown by organometallic vapor-phase epitaxy | The incorporation of both dopants and background impurities during the organometallic vapor phase epitaxial _x0002_OMVPE_x0003_ growth of GaAs, GaInP, and GaP has been significantly altered by the use of the surfactants Sb and Bi. Sb and Bi are isoelectronic with the group V host elements, and so ... | Physical and chemical processes; Surfactants isoelectronic; Electrochemical C-V profilometry | 2006 |
| 188 |
 |
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 |
| 189 |
 |
Stringfellow, Gerald B. | Dislocations in GaAs17-xPx | Dislocations, their origins, and their effects on photoluminescence efficiency have been studied in GaAs1-xPx single crystals grown by vapor phase epitaxy. Dislocations were observed using etch pit, optical-transmission microscopy, and x-ray topography techniques. Two types of dislocations are grown... | Photoluminescence efficiency; Growth mechanism; Optical transmission microscopy | 1969 |
| 190 |
 |
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 |
| 191 |
 |
Chaudhuri, Reaz A. | Three-dimensional singular stress field at the front of a crack and lattice crack deviation (LCD) in a cubic single crystal plate | A novel eigenfunction expansion technique, based in part on separation of the thickness variable, is developed to derive three-dimensional asymptotic stress fields in the vicinity of the front of a semi-infinite through-crack weakening an infinite plate made of a homogeneous cubic single crystal. C... | 2010-05-12 | |
| 192 |
 |
Tiwari, Ashutosh | CuBO2: a p-type transparent oxide | The authors report the synthesis of CuBO2, a p-type transparent oxide belonging to Cu-delafossite family. High quality thin films of CuBO2 were deposited on c-plane sapphire substrates by pulsed laser deposition technique. Detailed structural, optical, and electrical characterizations on these films... | Transparent conducting oxides; Delafossite series; CuBO2 | 2007 |
| 193 |
 |
Liu, Feng | Unique dynamic appearance of a Ge-Si Ad-dimer on Si(001) | We carry out a comparative study of the energetics and dynamics of Si-Si, Ge-Ge, and Ge-Si ad-dimers on top of a dimer row in the Si(001) surface, using first-principles calculations. The dynamic appearance of a Ge-Si dimer is distinctively different from that of a Si-Si or Ge-Ge dimer, providing a ... | Ge-Si Ad-dimer; Si(001); First-principles calculations; Energetics | 2000-12 |
| 194 |
 |
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 |
| 195 |
 |
Liu, Feng | Liu et al reply | In our Letter [1], we have demonstrated the plausibility of a structure for ?-cristobalite SiC2 consisting of domains of I Aid symmetry, and provided strong evidence against other proposed models, based on first-principles total energy and lattice dynamics calculations. We are pleased that the Auth... | beta-Cristobalite SiO2; Rigid unit modes; RUM; Transient domain formation | 1993 |
| 196 |
 |
Chaudhuri, Reaz A. | Transverse shear stress distribution through thickness near an internal part-through elliptical hole in a stretched plate | A semi-analytical post-processing method, termed the equilibrium/compatibility method here, is used for computation of hitherto unavailable through-thickness variation of transverse shear stresses in the vicinity of the circumferential re-entrant corner line of an internal part-through elliptical ... | 2010-03 | |
| 197 |
 |
Liu, Feng | Determination of the Ehrlich-Schwoebel barrier in epitaxial growth of thin films | We demonstrate an approach for determining the "effective" Ehrlich-Schwoebel (ES) step-edge barrier, an important kinetic constant to control the interlayer mass transport in epitaxial growth of thin films. The approach exploits the rate difference between the growth and/or decay of an adatom and a... | Ehrlich-Schwoebel barrier; Epitaxial growth; Step-edge barrier; Adatoms | 2006-11 |
| 198 |
 |
Liu, Feng | Magnetism of Al-Mn quasicrystals | The effect of symmetry and concentration of Mn on the magnetism of Al-Mn quasicrystals has been investigated through self-consistent density-functional calculations using molecular clusters and supercell band-structure schemes. A single Mn atom surrounded by 54 Al atoms in an icosahedral or a cuboct... | Al-Mn quasicrystals; Self-consistent; Density-functional calculations | 1993-07 |
| 199 |
 |
Tiwari, Ashutosh | Self-aligned passivated copper interconnects: a novel technique for making interconnections in ultra large scale integration device applications | We have developed a technique to grow self-aligned epitaxial Cu/MgO films on Si (100) using a Pulsed Laser Deposition Method. In this method we deposit a uniform film of Cu/Mg (5-7%) alloy over Si (100) at room temperature using TiN as an intermediate buffer layer. As a result of HRTEM (with spatial... | Passivated copper interconnects; Diffusion barriers; Copper diffusion; Tantalum nitride | 2002 |
| 200 |
 |
Scarpulla, Michael | SnS thin-films by RF sputtering at room temperature | Tin monosulfide (SnS) is of interest as a potential solar cell absorber material. We present a preliminary investigation of the effects of sputtering conditions on SnS thin-film structural, optical, and electronic properties. Films were RF sputtered from an SnS target using an argon plasma. Resi... | 2011 |