Materials Literature
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Extensive X-band ESR measurements have been made on the 3d transition metal intercalation compound M x TiS 2 (M=V, Cr, Mn, Fe, Co, Ni; 0≤ x ≤1) over the temperature range 300–77 K. The variations of the intra- and interlayer spacings with intercalation of guest atoms are presented. Fe and Ni intercalates do not show a…
Layered electrophotographic photoconductors using chloroindium chlorophthalocyanine have been investigated. An evaporated film of chloroindium chlorophthalocyanine has a broad and strong light absorption band in the visible to near-infrared region and its crystal structure is very stable. The photoconductor using chlo…
Magnetic properties of (1- x )Fe 2 TiO 3 – x Fe 2 O 3 with x near the percolation threshold x ∼0.2 have been studied by using single crystals. It has been found that 0.9FeTiO 3 –0.1Fe 2 O 3 exhibits typical characteristics of the cluster spin glass, while 0.79FeTiO 3 –0.21Fe 2 O 3 can be identified with the re-entrant…
Model systems with periodic boundaries in the shape of an arbitrary parallelepiped are discussed. The locus of minimum images with respect to a given atom is determined, and algorithms for computing minimum image distances, as well as locating significantly interacting atom pairs are presented. It is also shown that,…
The ``blue bronze'' ${\mathrm{K}}_{0.30}$${\mathrm{MoO}}_{3}$ has a charge-density wave (CDW) which forms at T=181 K. At temperatures below 181 K, nonlinear conductivity due to charge transport by the CDW has been observed. We have performed x-ray and elastic-neutron-scattering experiments which show that at onset the…
Diamond thin films have been formed by the newly proposed electron assisted chemical vapor deposition on SiC with a high growth rate (3∼5 μm/h). The obtained films have good crystallinity in the sense of electron and x-ray diffraction. Vicker’s hardness of the films is about 9000 kg/mm2. The influence of the electron…
Optical absorption and emission measurements are reported for the Cs2NaSmCl6 and Cs2NaYCl6:Sm3+ (1 or 30 mol %) systems under variable-temperature (10–298 K) conditions. Twenty-six crystal-field levels spanning 13 multiplets of the Sm3+ 4f 5 electronic configuration are located and assigned on the basis of the experim…
Indium tin oxide films have been grown by rf sputtering at various Ar-O2 mixtures, at low substrate temperatures (200 °C), and deposition rates (25 Å/min), followed by post deposition annealing (at 350 °C) in different ambients (O2, N2, and cracked ammonia). Influence of a reactive gas (oxygen) on the sputtering rate…
We examine the two- and three-point matrix probability functions for a two-phase random and homogeneous system of impenetrable spheres. For such a system, we give an exact analytical expression for the two-point matrix function S2 through second order in the number density of particles. Moreover, the two-point matrix…
Low-temperature magnetic susceptibilities yield an effective magnetic moment per W atom of (3.24\ifmmode\pm\else\textpm\fi{}0.10)${\ensuremath{\mu}}_{B}$ for both ${\mathrm{W}}_{0.05}$${\mathrm{V}}_{0.95}$${\mathrm{O}}_{2}$ and ${\mathrm{W}}_{0.08}$${\mathrm{V}}_{0.92}$${\mathrm{O}}_{2}$. This value suggests a transfe…
This paper points out a number of errors that have appeared in the literature concerning transmission-line models for metal grid reflectors (strip gratings and meshes) especially in regard to the design of laser mirrors and filter elements for use at submillimeter wavelengths. General formulas are given for the transm…
A flight experiment was performed on the eighth Space Shuttle mission to measure reaction of surfaces with atomic oxygen in the low earth orbital environment. More than 300 individual samples were exposed to ram (normal to surface) conditions for 41.75 hr leading to a total atomic oxygen fluence of 3.5 x 10 to the 20t…
Ion beam sputter-deposited thin films of Al2O3, SiO2, and a codeposited mixture of predominantly SiO2 with small amounts of a fluoropolymer were evaluated both in laboratory plasma ashing tests and in space on board shuttle flight STS-8 for effectiveness in preventing oxidation of polyimide Kapton. Measurements of mas…
We demonstrate that the equations of hydrodynamics for a simple compressible fluid, including nonlinearities and thermal fluctuations, display a transition, at sufficiently high densities and low temperatures, to a glass. The theory leads to predictions for the behavior of viscosities, sound speeds, and correlation fu…
Hopping of photoexcited carriers directly between localized, band-tail states gives rise to a new regime of energy relaxation which is manifested at low temperatures: For times shorter than a characteristic "segregation time," carriers hop directly to lower-energy states; at longer times, thermal excitation---resultin…
The lattice distortions of NbTe 4 and TaTe 4 are investigated by electron microscopy and electron diffraction. Evidence is presented for a high-symmetry distortion, with a space group of P4/mcc for sublattices and commensurate superlattices in both materials. Satellite dark-field images show discommensuration arrays w…
The role of initiator and activator concentrations on the whole process of ε -caprolactam anionic polymerization has been explored, with the aim of selecting the most suitable experimental conditions for the RIM process. The effects of the active species on high polymer yield, residual monomer content, higher oligomer…
The successful utilization of Reaction Injection Molding (RIM) to fabricate complex polyurethane shapes in a single step from relatively low viscosity streams has led to a search for other chemical systems which can be fabricated by the RIM process. The rapid polymerization of molten caprolactam by anionic catalysis h…
Optical second-harmonic generation has been applied to the study of clean Si(111) 2\ifmmode\times\else\texttimes\fi{}1 and 7\ifmmode\times\else\texttimes\fi{}7 surfaces. By an analysis of polarization dependences of the two reconstructions, the symmetry properties of the surfaces have been determined. The 2\ifmmode\ti…
A comparison of infrared spectra from individual teeth along the radula of a chiton (Polyplacophora, Mollusca) shows that the first-formed calcium phosphate mineral is amorphous. Over a period of weeks the mineral transforms to dahllite. The c axes of the dahllite crystals are aligned approximately perpendicular to th…