Materials Literature
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The electronic structure of fully oxidized polyaniline, pernigraniline, is investigated in the framework of the Su-Schrieffer-Heeger Hamiltonian, making use of an original renormalization technique. Among the family of polyanilines, pernigraniline is the only form to possess a degenerate ground state. It is shown to a…
Giant Shubnikov--de Haas oscillations have been observed in the high-${T}_{c}$ phase (${\ensuremath{\beta}}_{H}$) of an organic conductor \ensuremath{\beta}-(BEDT-TTF${)}_{2}$${\mathrm{I}}_{3}$. The frequency of the oscillations (${H}_{0}$=3730T) Corresponds to about one carrier per unit cell. The extraordinary large…
Alkali-halide single crystals are shown to grow from molecular beams under conditions systematically different from those for metals and elemental semiconductors, for reasons related to ionic bonding. Heteroepitaxy, and the occurrence of epitaxially stabilized new alkali-halide alloys and compounds, are discussed.
Analysis of data from Nd:YAG indicates a substantial experimental divergence from the standard theoretical results predicted for nonradiative energy transfer. A new model for correlated ion placement in the crystal is shown to completely explain the discrepancy.
Single-phase SnxGe1−x alloys with x up to 0.3 have been grown by molecular beam epitaxy. X-ray diffraction measurements indicate the layers to have the diamond crystal structure. The metastability of the alloys is apparent as increases in the growth temperature, layer thickness, or Sn composition cause phase separatio…
We show that a new concept of amphoteric native defects with strongly Fermi level dependent defect formation energy provides the basis for a unified explanation of a large variety of phenomena in semiconductors. Formation of Schottky barriers, particle irradiation induced compensation, doping-induced superlattice inte…
Using the tensor basis and utilising the Wigner-Eckart theorem, the authors obtain the matrix representations (μ00) and (μ10) of O 6 (ST) ⊃ O 3 (S) × O 3 (T). The isoscalar factors of O 6 (ST) × O 6 (ST) ⊃ O 6 (ST) ⊃ O 3 (S) × O 3 (T) are also calculated.
Abstract A new technique is reported for the surface grafting of polyvinylpyrrolidone (PVP) to hydroxylated solid surfaces. Free radical graft polymerization of vinylpyrrolidone onto vinylsilane–modified impermeable silica particles was carried out in an aqueous slurry reactor. The graft yield and the monomer conversi…
Abstract The wavelength sensitivity of a compounded extruded rigid poly(vinyl chloride) formulation to yellowing under exposure to filtered xenon radiation is determined using a cut‐on filter technique. Spectral sensitivity of the formulation in the absence and the presence of 2.5 phr of rutile titanium dioxide was ex…
Abstract Modern electrolysis processes for the hydrogen technology. This survey discusses all processes of water electrolysis after having emphasized the central role, which hydrogen plays in chemical technology and which it might play in a hydrogen economy, with the aid of some historical considerations and applicati…
The evolution of both the metric and topological properties of the microstructure for Ni pow- der compacts at the late stages of sintering(V_v~s0.90)has been investigated by means of stereological method.The effects of precompaction pressure and loose sintering have been stu- died and discussed.
The primary, alpha-secondary, beta-secondary, and beta'-secondary deuterium and primary 18O kinetic isotope effects on V/K for the dehydration of [(3S)-3-hydroxybutyryl]pantetheine by bovine liver crotonase (enoyl-CoA hydratase, EC 4.2.1.17) have been determined by the equilibrium perturbation method. The primary deut…
The permeation of deuterium (D) from the gas phase into solution in iron has been measured using a new method based on ion beam analysis. For bare metal surfaces the D uptake was observed to be limited by matrix diffusion through the bulk. The influence of chemisorbed oxygen on the D uptake rate was examined in detail…
A theoretical study of the electron-phonon interaction and anisotropic carrier mobilities in black phosphorus is presented. It is shown that the electron-phonon interaction is expressed in a deformation potential form in the rigid ion model and the long wave phonon approach. The deformation potential constants are cal…
Total energy pseudopotential calculations of missing dimer reconstructions on the Si(001) surface are presented. The authors have calculated the energy of the ideal unreconstructed surface and the energy of the (2*1) symmetric dimer, the (2*4) single missing dimer, the (2*2) single missing dimer and the (2*4) double m…
Valence band and core-level characteristics of sputter-deposited Fe–Cu, Fe–Ag and Fe–Cu–Ag alloy films have been studied by X-ray photoelectron spectroscopy using monochromatized Al Kα radiation. These films are composed of metastable bcc, fcc and amorphous phases depending on the alloy composition. Their valence band…
Optical absorptions in the tail region and the reflectivity at room temperature in the VUV region up to ∼40 eV are measured for YAG single crystals. Various optical constants are derived therefrom as functions of photon energy by means of the Kramers-Kronig relation. The Urbach rule parameters are determined experimen…
Hall mobility of photoexcited holes in the \(\varGamma_{7}^{+}\) valence band of Cu 2 O has been measured at low temperatures. On the basis of the theory of carrier-lattice interactions in polyatomic crystals the intrinsic scattering mechanisms of this substance have been clarified, for the first time, in a wide tempe…
We study the center model of Penrose lattices with a fivefold rotational symmetric axis in the framework of a tight-binding Hamiltonian. The inflation (or production) rules of ``finite Penrose patterns'' generated by repeated application of deflation and rescaling are found, which show a definite hierarchical structur…
Selectively excited emission and ${\mathrm{Tb}}^{3+}$\ensuremath{\rightarrow}${\mathrm{Ce}}^{3+}$ energy transfer in ${\mathrm{Y}}_{3}$${\mathrm{Al}}_{5}$${\mathrm{O}}_{12}$:Tb,Ce (YAG:Tb,Ce) at room temperature were studied. The selective excitation included a 266.0-nm laser pulse. The processes of ${\mathrm{Tb}}^{3+…