Materials Literature
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A particular interest in the properties of transition metal alloys at the present time is the problem of the occurrence of localised electron spins. There is also, particularly in the first period, the problem of ordered magnetic states. Recent work has established that suppression of localised spin may occur in mater…
The compounds Pd4Se and PdaS are isostruetural, space group P421c(D~d ), with eight palladimn atoms in general positions and two selenium (sulfur) atoms in positions 0, 0, 0; , , . For Pd4Se the palladium coordinates were determined to be x =0.374, y =0.232, z =0.154, and for Pd4S to be x =0.358, y =0.230, z =0.155. I…
Abstract A detailed study of the thermal expansion of silicon is made using an X‐ray powder technique, between room temperature and 900 °C. The values only agree with those of MAISSEL below 700 °C, the present values being higher above this temperature. It is found that Grüneisen's two‐constant formula cannot fit the…
Abstract Heats of polymerization of twelve vinyl monomers have been determined on an isothermal distillation calorimeter working at 74.5°C. Polar monomers were found to have their molar heats of polymerization appreciably dependent on the extent of association of the monomeric state in the medium of polymerization and…
The removal of residual volatile components from polymers is an operation of some importance in the plastics industry. A generalized, although somewhat idealized, model for continuous, wiped-film devolatilization of viscous polymer melts is presented which relates devolatilization capability to important geometry, ope…
The Curie points of K2ReCl6 and K2ReBr6 obtained from magnetic susceptibility measurements are 12.4±0.5° and 15.3±0.5°K, respectively, which confirm that cooperative-type transitions observed in the heat capacities of these compounds with maxima at 11.9±0.1° and 15.2±0.1°K, respectively, represent transitions to the a…
Thermodynamic data for reactions concerned in the corrosion of copper in waters containing dissolved oxygen and carbon dioxide are assembled and are used to demonstrate certain features of the corrosion processes. These include the extreme vulnerability of copper to attack, the critical effects of oxygen, and the inad…
R. M. Barrer and D. J. Ruzicka, Trans. Faraday Soc., 1962, 58, 2262 DOI: 10.1039/TF9625802262
Abstract In this paper a method is described for the numerical evaluation of phonon widths and shifts due to three‐phonon processes in an anharmonic crystal. With this method the δ‐function and principal value restrictions on the frequencies of the phonons participating in the three‐phonon processes do not have to be…
Abstract Sorgfältig gereinigte Lactone polymerisieren mit anionischen Initiatoren (metallisches Natrium, Naphthalin‐Natrium, Aluminiumalkyle) schon bei Zimmertemperatur zu hochmolekularen Polyestern (M̄ bis 100 000 und höher). Besonders wirksam sind Aluminiumalkyl/Wasser‐Systeme. Bei der Polymerisation des β‐Propiolac…
Abstract By polymerizing phenyl or n ‐butyl isocyanate in various solvents in the presence of anionic catalysts such as lithium or sodium alkyls, crystalline polymers were obtained. For both polymers, the I.R. spectra, the X‐ray diffraction spectra and other physical properties are reported. The possible structures of…
Activation of orthophosphates of the type with copper gives an efficient phosphor in some cases. The brightest phosphors found are and , with an emission peak (with 2537Aå excitation) at 4150 and 4600Aå, respectively. The properties of orthophosphates of the type with two kinds of alkali earth or alkali metal ions, re…
D. J. Greenland, R. H. Laby and J. P. Quirk, Trans. Faraday Soc., 1962, 58, 829 DOI: 10.1039/TF9625800829
Abstract Biotite samples were treated with NaCl‐NaBPh 4 solutions and various methods of separating the precipitated K from the resulting mixture were evaluated. As a result, a boiling NH 4 Cl solution method was adopted for K extraction experiments with small samples and a foaming method was used in the preparation o…
Oxygen-18 exchange between gaseous oxygen and cadmium oxide crystals has been studied in the temperature range 630° to 855°C. Since isotope equilibrium is not instantaneously established at the crystal surface an appropriate solution for this particular diffusion problem has been given. In this way it is possible to e…
A method for calculating the anodic polarization curves of binary alloys from those of their components is presented. Heterogeneous alloys can be treated as simple galvanic couples, but homogeneous alloys are subject to a modification of Tammann's concept of surface enrichment. Potentiostatic anodic polarization curve…
Abstract Die Herstellung hochmolekularer amorpher Äthylen/Propylen‐Copolymerisate (Äthylen/Propylen‐Kautschuk = APK) mit Z IEGLER mischkatalysatoren aus Vanadiumoxychlorid und Äthylaluminiumdichlorid bzw. Äthylaluminiumsesquichlorid wird beschrieben. Ein frisch hergestellter Mischkatalysator hat eine sehr hohe Aktivit…
Abstract Both the glass transition temperature and the melting point of poly(vinyl chloride have been found to increase as the temperature at which the ample is polymerized is decreased). The glass transition temperature changes from about 70°C. for polymer prepared at 125°C. to about 100°C. for polymer prepared at −8…
The tensile behavior of sapphire whiskers was measured at temperatures ranging from 25–2030°C. At room temperature, the tensile strength of the whiskers is size dependent and varies from several hundred thousand psi to 1 500 000 psi. With increasing temperature the strength decreases and becomes less size dependent. T…
A synthetic crystal of mullre, 2A120 a . SiO 2, was studied by X-ray diffraction methods. The structure was found to be describable as the result of the following changes imposed upon the structure of sillmanre: re-distribution of silicon and aluminium of tetrahedral coordination into a random way over the same set of…