Materials Literature
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The embedded-atom method is used to calculate the surface stresses and the interface stresses for several fcc metals and interfaces between them. While the surface stresses are all positive (i.e., they tend to put the underlying crystal in compression), in several instances (e.g., in the Pt/Ni system) negative interfa…
Perturbation formulas are derived for calculating the vibrational dynamic polarizability (αv) and hyperpolarizabilities (βv and γv ) of polyatomic molecules. These formulas, based on an initial harmonic oscillator approximation, include corrections for mechanical anharmonicity (cubic) terms in the vibrational potentia…
We have performed angle-resolved-photoemission experiments and local-density-functional (LDA) band calculations on NiO to study correlation and band effects of this conceptually important compound. Our experimental result suggests a dual nature of the electronic structure of NiO. On the one hand, the LDA band calculat…
Domain wall contributions to the dielectric, piezoelectric, and elastic properties of tetragonal ferroelectric ceramics, as discussed extensively in the past, are calculated. A simple model shows that the motion of 90° domain walls causes a shear deformation and an approximately homogeneous electric field in the grain…
The full-potential linear-muffin-tin-orbital method in combination with the local-density-functional theory is used to calculate the equilibrium lattice constant, the cohesive energy, the bulk modulus and its pressure derivative, the elastic constants, the Kleinman internal displacement parameter \ensuremath{\zeta} th…
A valence-force-field model has been used to study the lattice dynamics of molybdenum disulfide single molecular layers. A comparison between the room-temperature Raman spectra of aqueous suspensions and the calculated phonon-dispersion curves for single layers of ${\mathrm{MoS}}_{2}$ with trigonal prism and octahedra…
Absolute total cross sections for scattering of electrons by water molecules measured in the 4-20 eV incident energy range using a linear electron transmission device are presented. The results are compared with previous data.
The flow stress of many metals is known to vary more strongly with strain rate epsilon above a critical value epsilon c than below it. An analysis of previous authors' measurements on copper indicates that the value of epsilon c varies systematically with specimen size. An estimate of inertial stress shows that inerti…
Total electron scattering cross sections for C 2 H 4 , C 2 H 6 , C 3 H 6 (propene and cyclopropane) and C 3 H 8 have been measured in the energy range between 4 and 500 eV. Measured results show a remarkable isomer effect and dependence on the geometrical dimension of the molecule.
The locally restricted motion of hydrogen and deuterium which are trapped at Cd acceptors in silicon has been studied by perturbed-angular-correlation spectroscopy. Close Cd-H and Cd-D pairs were identified by their characteristic electric-field gradients. The kinetics of these complexes was extracted directly from th…
Preparation of semiconducting vanadium silicate glasses by the sol-gel route and the results of electrical measurements are reported for the first time. The temperature dependence of the electrical conductivity has been analyzed in terms of small polaron as well as percolation models.
High resolution neutron scattering studies of vibrational spectra (2-800 meV) were carried out on the in -, delta ' and delta -phases of titanium hydride, obtained after high pressure treatment. The observed splitting of the fundamental optic peak in the delta -phase spectrum can be explained by a strong H-H interacti…
Porous silicon membranes have been formed by electrochemical etching through wafers up to 500 μm in thickness. The results show that there is essentially no limit to the thickness of porous silicon layers and that self-supporting porous structures can be formed by this method. In addition, the membranes are structural…
Binary SmFe12 and Sm(Fe,T)12 films, where T =Ti and V, crystallized into the ThMn12-type structure, have been synthesized as sputtered films such that the c axes of the crystallites are oriented perpendicular to the film plane. It has been possible to synthesize Sm(Fe,T)12 films which exhibit a very dominant (002) tex…
Electrical conduction along conducting layers between grains in chemical vapor deposited polycrystalline diamond films has been studied. The dc current-voltage characteristic consists of an ohmic region at low voltages and a highly nonlinear region at high voltages. As-grown films are dominated by the ohmic conduction…
We report on a mean-field thermodynamic analysis of AB random copolymer melts with (backbone) composition correlations that reflect realistic polymerization conditions. Depending on the strength and sign of these correlations, multiple homogeneous phases, periodic mesophases, or disordered mesophases are possible. We…
Explicit formulae are found for the electric field vectors of the ordinary and extraordinary modes produced when plane waves of p or s polarization are incident on an arbitrary face of a uniaxial crystal. The angle of incidence is unrestricted, and the anisotropic medium may be absorbing. The reflection amplitudes r p…
We report on a Raman spectroscopic study of polycrystalline diamond films using a wide range of incident photon energies (1.16–4.82 eV). The scattering intensity of amorphous sp2-bonded carbon is found to vary considerably as a function of the incident photon energy as compared to the strength of the 1332 cm−1 Raman l…
Nucleation, growth, and dissolution of crystals have been studied by stereochemical approach involving molecular recognition at interfaces. A methodology is described for using ;;tailor-made'' additives designed to interact stereospecifically with crystal surfaces during growth and dissolution. This procedure was inst…
Abstract Tensile and impact properties of the ternary system polypropylene (PP)/ethylene propylene diene elastomer (EPDM)/glass fiber (GF) and the corresponding binary systems PP/EPDM blend and PP/GF composite are studied. Results are presented and analyzed as functions of compositional variables, viz., (i) matrix PP/…