Materials Literature
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The phonon dispersion relations and the elastic constants are evaluated for Wigner electron crystals near the critical coupling strength for melting in the fully quantal regime at zero temperature. The structures considered are the body-centred and face-centred cubic lattices in dimensionality D = 3 and the triangular…
The formation of stress-induced martensite in superelastic NiTi was studied by neutron diffraction during uniaxial compressive loading and unloading. The respective phase fractions were determined as a function of the applied stresses using a Rietveld refinement with a March–Dollase texture formulation. Before loading…
We report the electrical conductivity between 2 and 300 K for across the composition-controlled metal - insulator (m - i) transition. Using a method first suggested by Möbius, we identify the critical concentration to be 0.3 for the m - i transition. The negative temperature coefficient of resistivity observed at low…
The correlated quasiparticle energies for valence bands of polyethylene have been calculated, ab initio, employing many-body perturbation theory. Electron correlation effects for the bands vary from 1.5 to 5.4 eV. The MBPT(2) band energies accurately explain the measured photoelectron spectra (XPS, UPS) of polyethylen…
We report on the thermally activated hysteresis relaxation effects in (La,Sr)CoO3/ (Pb,La)(Zr,Ti)O3/(La,Sr)CoO3 thin film ferroelectric capacitors. Films cooled in oxygen deficient ambients exhibit a marked voltage offset in the hysteresis loops. Upon the application of a dc bias voltage or unidirectional pulses of th…
Far-infrared ellipsometric spectra of n-type (100) GaAs display sharp features in the range of the longitudinal optical phonon of intrinsic material, originating in the surface depletion region. We compare measured relative ellipsometric phase shifts with model calculations of the graded depletion layer. A very good a…
Results on the conductivity as a function of temperature of carbon black - polymer composites with a wide range of loadings are presented and discussed. Inter-particle transfers dominate the resistivity in the low-loading composites, and the conductivity is described quantitatively by the theory of fluctuation-induced…
The time dependence of the size, shape, and concentration of ordered grains in a quenched block copolymer melt was studied by depolarized light scattering. Block copolymers are ideal systems for kinetic studies because the single scattering limit applies during all stages of grain growth. In the early stage, where the…
Coherent inelastic neutron scattering results obtained at different temperatures in the normal phase of betaine calcium chloride dihydrate (BCCD) are reported here. The experimental characterization of the mechanism which induces the transition from the parent phase to the incommensurate phase of BCCD is described. We…
In spite of large concentrations of phosphorus being incorporated into diamond, the material often remains insulating. It is argued that this occurs through the formation of phosphorus-vacancy complexes which are deep acceptors and compensate any donor. The complex is analyzed using a first-principles cluster method.…
I have measured the resistance and linear expansion of a disordered carbon-black–polymer composite as a function of temperature from 25 to 180 °C. The sample resistance and thickness both increases monotonically as a function of temperature, with precipitous increases at the polymer melt temperature. The resistance ve…
Using a density functional theory for Lennard-Jones fluids, we find significant bcc (body-centered-cubic) character in both the planar interface between the stable fcc (face-centered-cubic) crystal and the stable liquid and at the interface of the critical fcc nucleus in a metastable liquid. We introduce an order para…
High-temperature powder x-ray diffraction data are presented for perovskite between 293 and 1523 K. The temperature-dependence of superlattice intensities and cell parameters suggests a sequence of phase transitions from the room temperature orthorhombic (Pbnm) structure to a tetragonal (I4/mcm) polymorph at temperatu…
It is well known that fast ionic conductivity can be obtained by doping modified oxide glasses with a metal-halide salt. The role of the dopant salt, apart from providing additional charge carriers, for the ionic conductivity has been a much debated issue. Using conductivity and density data for different host glasses…
In this paper we propose a method aiming at a quantitative study of the glass transition in a system of interacting particles. In spite of the absence of any quenched disorder, we introduce a replicated version of the hypernetted chain equations. The solution of these equations, for hard or soft spheres, signals a tra…
The influence of electron-electron scattering on quasiparticle lifetimes in graphite is calculated. In the limit when the Fermi surface is reduced to isolated points in the Brillouin zone, the suppression of screening leads to deviations from conventional Fermi liquid behavior. The inverse lifetime increases linearly…
We propose a phenomenological model which accounts for the entire sequence of subphases exhibited by antiferroelectric smectic liquid crystals. It incorporates, up to the second neighbour, both chiral and nonchiral interactions between the smectic layers. Phase diagrams are presented as functions of appropriate parame…
Transmission and reflection of Gaussian beams from a general anisotropic multilayer structure are investigated. The principal axes of the layers are oriented arbitrarily with respect to each other and with respect to a fixed reference coordinate system. The Gaussian beam is assumed to have an arbitrary angle of incide…
The effect of (gamma) and proton radiation on the optical attenuations at 980, 1300, and 1550 nm has been measured in two Lucent Technologies erbium-doped fibers (EDFs) designed for use in amplifiers pumped at 980 nm. Growth of the induced loss at the 3 wavelengths followed a power law of dose with an exponent of appr…
Abstract For corrigendum see DOI: 10.1002/anie.199628811