Materials Literature
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Grazing-incidence x-ray scattering (GIXS) techniques have been used to study the local and intermediate-range order in photodiffused amorphous Ag-${\mathrm{GeSe}}_{2}$ thin films and a variety of Ag-Ge-Se alloys. Using synchrotron-radiation sources, the GIXS technique can be used in conjunction with radial-distributio…
A new approach to the study of plastic flow in semiconductors is introduced. By analyzing relaxation of misfit strain in metastable strained-layer structures, the effects of resolved shear stress up to several GPa can be examined, at least an order of magnitude larger than is accessible using conventional loading tech…
The linear coefficient of thermal expansion of the fcc metals Cu, Ag, Au, Ni, Pd, and Pt are computed using the semiempirical embedded-atom method to determine the energetics. The results are in good agreement with experiment. The importance of including the equation of state in the determination of the empirical func…
We study the profile of a thin liquid film completely wetting a rough solid surface. The long-wavelength undulations of the liquid interface follow those of the solid surface, while short-wavelength undulations are strongly damped. There is Lorentzian damping of wavelengths smaller than the healing length ξ determined…
Vanadium nitride (NaCl structure, [N]/[V]\ensuremath{\ge}0.99, space group Fm3\ifmmode\bar\else\textasciimacron\fi{}m, a=4.1328(3) A\r{} at 298 K) transforms at 205(5) K into a tetragonal, noncentrosymmetric low-temperature modification [space group P4\ifmmode\bar\else\textasciimacron\fi{}2m, a=4.1314(3) A\r{}, c=4.11…
The elastic constants of an amorphous binary soft sphere alloy have been determined by molecular-dynamics simulations. The shear modulus of the amorphous solid is found to vanish at the glass transition temperature, below which it is significantly smaller than the value found for a polycrystalline sample under the sam…
Raman scattering from one- and two-magnon excitations in various rare-earth orthoferrites are studied. The magnetic in-plane and out-of-plane anisotropy energies of these systems are obtained and discussed based on the two-sublattice model of ironspins. Detailed temperature dependence of the frequencies of two \(k{\co…
Dielectric relaxations in undiluted cis-polyisoprene (cis-PI) with narrow molecular-weight distribution were investigated. The normal mode process due to fluctuation of the end-to-end distance and the segmental mode process due to the local segmental motions were observed. The average relaxation time τn for the normal…
A recent measurement of the force-height relation for two layers of end-grafted polystyrene chains in toluene is shown to be in excellent quantitative agreement with our recent theory, which is an exact solution of self-consistent field equations applicable in the limit of strongly stretched chains. Two undetermined p…
The effects of ArF excimer laser irradiation on dehydrated high-purity silica glass were investigated on both the optical-absorption bands due to oxygen-deficient centers (ODC) and the formation of ${E}^{\ensuremath{'}}$ centers. With an intense uv flux from an excimer laser, an ${E}^{\ensuremath{'}}$-center density o…
An experimental and theoretical study of the lattice dynamics of MP${X}_{3}$ layered compounds (M=Mn,Fe,Ni,Zn; X=S,Se) has been carried out. We present room-temperature infrared and Raman spectra and the phonon dispersion curves calculated in the framework of an axially symmetric force-constant model. The parameters o…
The photodetachment cross section of the lithium anion is studied in the coupled cluster polarisation propagator approximation (CCPPA). The discrete pseudospectra are analysed by moment theoretical methods. The all-electron CCPPA cross section of this work differs considerably from older calculations that involve pseu…
The rectified Barkhausen noise envelope, induction rate dB/dt signal, and hysteresis curve have been measured simultaneously for an annealed and plastically deformed mild steel specimen. The two peaks in the Barkhausen noise envelope of the annealed specimen occurring in the knee regions of the hysteresis curve are du…
The gene for leucine dehydrogenase (EC 1.4.1.9) from Bacillus stearothermophilus was cloned and expressed in Escherichia coli. The selection for the cloned gene was based upon activity staining of the replica printed E. coli cells. A transformant showing high leucine dehydrogenase activity was found to carry an about…
The Wright etch [M. W. Jenkins, J. Electrochem. Soc. 124, 757 (1977)], hitherto used to reveal defects in silicon, has been examined as a defect etchant for GaAs epitaxial layers on silicon. Various calibration techniques, including transmission electron microscopy of etched epitaxial layers, have been used to establi…
A unified model of the low-frequency dielectric response in KNbO 3 is proposed to reconcile all the infrared, Raman, hyper-Raman and dielectric results obtained in all phases. This model, based on the coexistence of a soft phonon and a relaxation mode, is applied to fit new Raman scattering results and to analyse alte…
In this paper we examine the dielectric and structural properties of hard polarizable multipolar models for liquid water. The theoretical results were obtained by solving the self-consistent mean field (SCMF) approximation together with the reference hypernetted-chain (RHNC) theory. The dielectric constants are in goo…
A new experimental approach for determining photoionization matrix elements which avoids the spin analysis of the photoelectron is presented for the case of 2p photoionization of atomic magnesium by 80-eV photons. Our experimental results clearly demonstrate the inadequacy of presently available theoretical calculatio…
It is shown via state-of-the-art theoretical calculations that self-diffusion in diamond is dominated by vacancies, independent of the position of the Fermi level. This is very different from self-diffusion in silicon and germanium, where vacancies, interstitials, and direct-exchange mechanisms all have comparable act…
Extensive first-principles calculations are presented for the formation energies and migration barriers of elementary defects in graphite, as well as for the activation energy of atomic exchange. The calculations show that the long-held view, that atomic diffusion in graphite occurs via the direct-exchange mechanism,…