Materials Literature
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By a suitable combination inside the muffin-tin sphere of a radial solution to the Schrodinger equation and its energy derivative, the dependence of the APW matrix elements on the energy E used to construct the basis functions can be greatly reduced. This has a number of advantages. The authors present an application…
Although a considerable body of data exists on the parametrization of the ground-state splittings of S-state ions in crystals, relatively little progress has been made in obtaining a quantitative understanding of the mechanisms which determine these parameters. In the course of summarizing our present understanding, w…
The paper examines states in the gap in amorphous silicon and chalcogenides and their effect on photoconductivity, luminescence and drift mobility. It is supposed that carriers in an ‘ideal’ glassy semiconductor without defects would move by hopping at the band edge at low temperatures and by excitation to a mobility…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMelting Point Depression and Kinetic Effects of Cooling on Crystallization in Poly(vinylidene fluoride)-Poly(methyl methacrylate) MixturesT. Nishi and T. T. WangCite this: Macromolecules 1975, 8, 6, 909–915Publication Date (Print):November 1, 1975Publication History Publishe…
A simple technique is described for ascertaining trial models for the structures of perovskites. The method relies on an understanding of the fundamental components of the structure. Rules are given for determining trial models rapidly.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTX-ray photoelectron studies on some oxides and hydroxides of cobalt, nickel, and copperN. S. McIntyre and M. G. CookCite this: Anal. Chem. 1975, 47, 13, 2208–2213Publication Date (Print):November 1, 1975Publication History Published online1 May 2002Published inissue 1 Novemb…
Single crystals of SnxGe1-xTe(x=0.75 to 0.91) have been grown by the bridgman method for ultrasonic measurements of the sound velocities and the attenuation near the transition temperature. The results can be qualitatively interpreted in terms of an electrostrictive-type coupling between strain and order parameter and…
Abstract Die derzeitigen Ansichten über Startstellen, Mechanismen und Folgeprodukte der thermischen HCl‐Abspaltung aus PVC werden kurz erörtert. Die Kinetik der thermischen Dehydrochlorierung von unstabilisiertem und mit 0,05 bis 2,0 Gew.‐% Di‐n‐octylzinn‐di‐thioglykolsäure‐2‐äthylhexylester (I) stabilisiertem PVC wir…
Abstract The solubility of vinyl chloride monomer (VCM) in PVC powders has been studied by equilibrium vapor pressure and microbalance gravimetric techniques at temperatures from 30 to 110°C. At temperatures and VCM concentrations above the glass transition, the solubility closely follows the Flory‐Huggins equation wi…
Lattice energy calculations based on the Born model are used to examine the possible structures of defect clusters in non-stoichiometric FeO. The basic cluster is identified as a complex of four cation vacancies and one tetrahedral Fe 3+ ion (or 4:1 cluster) which is formed as a result of a large Coulomb term favourin…
A convergent perturbation scheme known as the layer-doubling method is used to determine the chemisorption position and bond length of an oxygen $p(2\ifmmode\times\else\texttimes\fi{}1)$ overlayer on W(110) surface. The use of perturbation treatment allows accurate and economical determination of surface crystallograp…
Thin films play a dominant role in modern technology. They appear as vital elements in integrated circuits as well as superconducting elements and solar energy conversion structures. Thin films are used both as active structures of precisely controlled thickness and area, and passive structures for connection to, or i…
The effective resistivity is calculated for a simple cell structure by means of the Boltzmann equation. In less heavily deformed metals the cell structure has only a negligible effect on the residual resistivity. In heavily deformed metals the observed DMR is in the same order of magnitude as that arising from the pre…
Nominally undoped YAG crystals become brown, when they are irradiated with hard rays at room temperature (RT). Investigations of absorption and fluorescence are discussed. Two fundamental types of coloration-independent fluorescence can be correlated with two fundamental types of coloration of nominally pure crystals…
Mössbauer spectra of several samples of the spinel system Fe3−xAlxO4 with 0 ≦ x ≦ 1.5 were obtained at room temperature and analysed. For x < 0.9 the spectra of the samples show several Zeeman patterns, which are attributed to tetrahedral and octahedral iron cations. With x > 0.9, the spectra show no theoretical Zeema…
The crystal structure of (CH3NH3)2MnCl4 is determined by neutron diffraction at 404 and 293 K in order to obtain a microscopic description of the second-order structural phase transition at 393.8 K. The high temperature phase has a disordered K2NiF4-type structure (I4/mmm). The ordered structure at room temperature (A…
A new method is proposed for the analysis (vacancy or interstital) of dislocation loops by means of the so-called inside-outside contrast. A simple and straightforward recipe is developed which is applicable in the same manner to loops of edge and of non-edge type irrespective of the loop orientation within the transm…
(CH3NH3)2CdCl4 is found to be isotructural at room temperature with (CH3NH3)2MnCl4 having the orthorhombic space group Cmca. A high temperature phase transition to a tetragonal phase could not be observed because of a decomposition slightly above 383 K. Two low temperature phase transitions are detected by means of DT…
After a comparison of the β-, ϵ-, γ-, and δ-type GaSe crystal structures, the different interlayer interactions are discussed. New values for the intralayer interatomic distances Se–Ga = 2.463 (15) Å, Ga–Ga = 2.457 (18) Å, and the interlayer distance Se–Se = 3.880 (15) Å are proposed. These are mean values for the δ-t…
High pressure optical measurements have been made on two spiropyrans dissolved in films of polystyrene (PS) and polymethyl methacrylate (PMMA). Three types of studies were made. (1) In the pressure region 30–140 kbars we observed pressure induced coloration (piezochromism) which was independent of time, rate of pressu…