Materials Literature
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The free energy and the static elastic constants of a hard-sphere glass are calculated using density functional theory. More specifically, Bennett's glass model is used where the packing fraction of random closed packing, eta RCP , is taken as an adjustable parameter. As regards the density functional, the modified we…
Luminescence decay curves have been measured for the Eu 3+ emission and Tb 3+ emission in the cubic crystals Cs 2 NaTb 1-x Eu x Cl 6 at 80 and 293 K using pulsed dye laser excitation into the 5 D 4 state of Tb 3+ and the 5 D 1 state of Eu 3+ . For excitation of Tb 3+ , efficient energy transfer occurs to the 5 D 0 sta…
The scaling equations which determine the master functions for the beta -relaxation process within the mode coupling theory of supercooled liquids are reformulated such that a direct numerical solution becomes possible. Tables are presented that allow an accurate derivation of the scaling function and susceptibilities…
We report the observation of saturation with chain length of the second hyperpolarizability of a series of long, well-defined, conjugated oligothiophenes. This saturation occurs at the same length as that of the band gap and of the polarizability, and is attributed to a saturation of the effective conjugation length.…
We have observed anomalously enhanced self- (tracer) diffusion in systems of polymerlike breakable micelles. We argue that it provides the first experimental realization of a random walk for which the second moment of the jump-size distribution fails to exist (``Levy flight''). The basic mechanism is the following: Du…
Using the transient hot-wire method, thermal conductivity and heat capacity per unit volume are measured for solid and liquid phases and glassy crystal states of cyclooctanol, and information is provided on the phase diagram under high pressure. A new solid phase (III) is detected and characterized as a normal crystal…
The data are obtained of the electrical activity of Fe, Ni, Mn, Cu, Te, Re, W in β-boron. These dopants are shown to be donors or acceptors depending on their disposition in nonequivalent voids of the lattice. Some information on the conduction mechanism and on the density of localized states in doped β-boron is also…
Thin film capacitors of AlNd2O3Al structure are fabricated by the resistive heating method under a vacuum of 2.66 × 10−3 Pa. The thicknesses of the dielectric films are measured by a multiple beam interferometer. Aging, annealing, and dielectric properties are studied in the frequency range 1 to 30 kHz at various te…
The plasmon excitation spectrum for a multiple-quantum-well superlattice with rectangular defect barriers in each quantum well is calculated in the random-phase approximation. It is demonstrated that both the intersubband and the intrasubband plasma frequencies can be effectively tuned subject to variations of the par…
The phonon-drag thermoelectric power ${\mathit{S}}_{\mathit{g}}$ in ${\mathrm{Al}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$As/GaAs heterojunctions at low temperatures (\ensuremath{\lesssim}5 K) is theoretically investigated based on the Cantrell-Butcher theory. The experimental data are well e…
Cs + 2(C 10 H 20 O 5 )•K − (I) cristallise dans C2/m avec a=11,537, b=13,679, c=10,624 A, β=90,12 o , Z=2, affinement jusqu'a R=0,067. Rb + 2(C 10 H 20 O 5 ); Rb − cristallise dans C2/m avec a=11,635, b=13,855, c=10,556 A, β=88,82 o , Z=2, affinement jusqu'a R=0,053. Les deux composes sont isostructuraux avec Rb + (15…
Highly conductive polypyrrole complexes obtained from chemical polymerization and oxidation of pyrrole by ${\mathrm{FeCl}}_{3}$ were studied by x-ray photoelectron spectroscopy. Properly deconvoluted Cl 2p core-level spectra of the complexes suggest that the chlorine dopant can exist in three chemical states. Thus rea…
A new liquid-crystalline phase has been discovered in a broad temperature region between the cholesteric and smectic-A phases for the mixture of cholesterylnonanoate and nonyloxybenzoic acid. This phase is a helical smectic A with local smectic ordering, helical macrostructure, significant rigidity in shear deformatio…
The adsorption of triethylgallium on the GaAs (100) (4×1) surface has been studied using the techniques of low energy electron diffraction, x-ray photoelectron and Auger spectroscopies, high resolution electron energy loss spectroscopy and temperature-programmed desorption. Condensed multilayers of the organometallic…
Electronic-structure calculations using the ab initio generalized-valence-bond approach have been used to investigate the structure and bonding of silicon clusters ${\mathrm{Si}}_{3}$--${\mathrm{Si}}_{10}$. While several previous studies of the structures of these clusters have been presented, this is the first to pro…
Optical phase conjungation using an amorphous silicon/ferroelectric-liquid-crystal light modulator shows an optical response of 100 microsec with a diffraction efficiency of 8.5% for an incident optical intensity of 1 mW/cm(2).
Azimuthal diffraction patterns of 1s and 2s photoelectrons, of plasmon-loss peaks and inelastic-background intensities, as well as of medium-energy electrons, are presented for polar angles of 45\ifmmode^\circ\else\textdegree\fi{} and 55\ifmmode^\circ\else\textdegree\fi{} off the surface normal of a clean Al(001) crys…
The notion of zitterbewegung and the resulting formalism, originally proposed for relativistic quantum dynamics, is applied to describe the acceleration of a nonrelativistic electron moving in a crystal, due to the periodic force experienced. A general linear-combination-of-atomic-orbitals (LCAO) approach is developed…
The electroreflectance spectra of the halogen-bridged mixed-valence Pt complexes, [Pt(ethylenediamine${)}_{2}$][Pt(ethylenediamine${)}_{2}$${\mathit{X}}_{2}$](${\mathrm{ClO}}_{4}$${)}_{4}$ (X=Cl, Br, and I), have been measured. Electric-field-induced new absorption bands that can be assigned to optically forbidden cha…
It is predicted that in a charge-density-wave (CDW) ring-shaped conductor, placed in an external vector-potential field, there should appear a new Aharonov-Bohm contribution to the magnetic susceptibility and the electrical conductivity oscillating as a function of the flux with the period ${\mathrm{\ensuremath{\Phi}}…