Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
Optical absorption and photoluminescence spectra in the range 1.2–2.2 eV have been measured in free-standing films of porous Si under hydrostatic pressures up to 6.4 GPa at room temperature. The absorption rises nearly exponentially in the low energy region. Under pressure, the whole spectrum shifts toward lower energ…
A new tight-binding-bond approach to interatomic forces in liquid aluminum--transition metal (AL-M) alloys is presented. It is shown that the bond order depends strongly on the strength of the pd hybridization in the A-M alloy, leading to nonadditive potentials with a strong preference for the formation of a pair of u…
The static and dynamic magnetic responses of HoPO 4 and ErPO 4 have been studied by means of neutron spectroscopy and magnetic susceptibility measurements. The inelastic neutron scattering spectra exhibit well-defined transitions characteristic of crystal-field excitations of the rare-earth ions. A comparison of the n…
It was found that a high concentration of holes was generated without any post-annealing by boron ion implantation into silicon in the high-dose region of more than 1×1016 cm−2. X-ray photoelectron spectroscopy and Fourier transform infrared absorption spectrum revealed that B12 icosahedra were created just after impl…
The influence of hydrostatic pressure on the temperature dependence of the optical birefringence and ultrasonic velocities is studied in the vicinity of the phase transition temperatures of Cs 2 HgBr 4 , Cs 2 CdBr 4 and Cs 2 HgCl 4 crystals. The new polycritical triple points which separate the normal, incommensurate…
Electrochemically etched silicon wafers can be utilized as transparent host matrices for a variety of luminescent media. Highly efficient (≳1%) photoluminescence across the entire visible range is demonstrated here using organic-dye-activated porous glass layers on Si wafers. Coumarin, xanthene, and oxazine dyes are u…
Researchers have synthesized a compound, [beta]-C[sub 3]N[sub 4], whose properties correspond to those predicted from theory. The synthesis of this compound, which is carbon nitride in the [beta]-Si[sub 3]N[sub 4] structure, shows that theory can point the way toward the creation of materials with hardness comparable…
Pulsed laser ablation of graphite targets combined with an intense, atomic nitrogen source has been used to prepare C-N thin film materials. The average nitrogen content in the films was systematically varied by controlling atomic nitrogen flux. Rutherford backscattering measurements show that up to 40 percent nitroge…
The crystal contains three independent five-coordinate monomers of chloro{2,2'-[o-phenylenebis(nitrilomethylidyne)]diphenolato-N,N', O,O'}iron(III). The distances Fe(1)-Fe(1A), Fe(1)-Fe(1B) and Fe(1A)-Fe(1B) are 7.175 (1), 7.683 (1) and 7.207 (1) A, respectively. The planes of the ligand groups of the two neighbouring…
Abstract The thermal properties of epoxidized natural rubber (ENR) have been found to improve upon hydrogenation in a solution phase, in the presence of a homogeneous catalyst, at 50°C. The hydrogenated ENR shows higher T max values in the DTG scan and, upon aging, the change in carbonyl concentration is less as compa…
In order to investigate the basic properties of pseudoelasticity of TiNi shape memory alloy, tensile tests with various maximum strains at constant temperature were performed. Based on the experimental results, dependence of the stress-strain curve in the pseudoelastic region on maximum strain and temperature was disc…
Abstract The aim of the work presented here is to develop a computer simulation technique which will predict the surface structure, the morphology and the rate of growth of carbonates. The technique is based on energy minimization in which all atom positions are varied until the lowest energy configuration is achieved…
Abstract The cyclic voltammograms of polyaniline prepared electrochemically were examined in the range −0.2 to 1.0 V vs. SCE in the presence and absence of aniline in the acqueous solution of HBF 4 . Cyclic voltammetry studies show that the polymeric film suffers degradation when the potential exceeds +0.85 V, and bel…
We present a chemical perturbation method for surface-structure determination by low-energy electron diffraction (LEED). It is based on tensor LEED theory and is able to substitute selected surface atoms by other chemical species making full dynamical calculations for the structure unnecessary. The potential of the ap…
The electromigration characteristics and kinetics of damage formation for Al(Cu,Si) line segments on a continuous W line and Al(Cu)/W two-level interconnect structures have been investigated. The mass transport as a function of temperature was measured using a drift-velocity technique. The flux divergence at the line/…
Polycrystalline samples of Ba2Cu2xZn2−2xFe28O46 (0≤X≤1) X-type hexaferrites were prepared by the classical ceramic method. Low-temperature magnetic properties and Curie temperature were investigated. The substitution of Zn2+ ion with Cu2+ ion leads to a decrease of the magnetic moment and an increase of Curie temperat…
We study theoretically the collective modes in charge-density waves in the presence of long-range Coulomb interaction. We find that earlier works by Takada and his collaborators are inadequate since they introduced inconsistent approximations in evaluating a variety of correlation functions. The amplitude mode is unaf…
Magnetic and structural studies of giant metal (M)-insulator (I)-metal reentrant transitions in the partially deuterated molecular conductors (DMe-DCNQI- d n ) 2 Cu ( n =2, 3) are presented. In the insulating phase, Curie-Weiss-like susceptibilities with reduced Curie constants and diffusive satellite reflections show…
The optical-absorption edge of zinc-blende-structure boron nitride has been measured at high pressure to 1.8 GPa using a sapphire-anvil cell. The effect of pressure on the minimum band gap is found to be 6.0 meV/GPa, which is greater than twice the value found in recent ab initio calculations.
Abstract Ethylene‐propylene‐diene rubber (EPDM) and isobutylene‐isoprene rubber (IIR) were compounded, precured to a low degree, and then were blended with natural rubber (NR). The compounding ingredients for NR were then added and the final curing was done. NR/EPDM and NR/IIR blends, prepared using this method, were…