Materials Literature
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The crystal structure of the new complex, CH3NH3NiCl3, has been determined. The compound crystallizes in the space group Cmcm with a=6.94, b=14.94, and c=5.95 Å. Each nickel ion has a distorted octahedral coordination with two chloride ions at 2.405 Å and four chloride ions at 2.351 Å. Adjacent octahedra along the c a…
The infrared absorption of single crystals of sodium formate has been measured in the region of 250 cm −1 to 4 000 cm −1 . Thin sections cut perpendicular to the unique axis were employed and spectra were recorded with light polarized at various angles in this plane. It has been possible to assign unambiguously all of…
The heat capacity of high-purity alpha uranium has been determined from 1.7 to 23\ifmmode^\circ\else\textdegree\fi{}K and smoothed into previous data at 25\ifmmode^\circ\else\textdegree\fi{}K. These heat capacities are significantly lower than the values reported by other investigators. The values for $\ensuremath{\ga…
A power series for the free energy is derived in the linear anharmonic approximation. This free energy is expressed in terms of a complete set of microscopic order parameters which determine the ionic displacements in the ferroelectric transition. In general this complete set of microscopic order parameters is larger…
The generation of electrons and holes in anthracene crystals by x rays from a 600-kV pulsed x-ray source was studied. The average energy deposited per electron-hole pair created $W$ was found to be 3\ifmmode\times\else\texttimes\fi{}${10}^{3}$ eV. The number of carriers generated was independent of temperature from --…
The Toyozawa theory of the electronic polaron and the related Haken-Schottky theory of the optical dielectric function are applied to the alkali and silver halides and to the rare-gas solids. It is found that for most of these crystals the above dynamical theories reduce to a static limit. This in turn indicates that…
Experiments with this scanning microscope have produced extremely encouraging results so that we feel Confident in predicting high resolution and high contrast after some obvious modifications are made in the system, such as providing a good objective lens. Experience with conventional lenses indicates that the instru…
Neutron-diffraction measurements have been made on single-crystal specimens of holmium at temperatures ranging from room temperature to 4.2\ifmmode^\circ\else\textdegree\fi{}K. Below the N\'eel temperature of 133\ifmmode^\circ\else\textdegree\fi{}K, the moments order in a helical structure in which the $c$ axis is the…
The dielectric properties of single-crystal and ceramic BaTi${\mathrm{O}}_{3}$ and of single-crystal SrTi${\mathrm{O}}_{3}$ were investigated as functions of hydrostatic pressure to 25 kbar and temperature to 150\ifmmode^\circ\else\textdegree\fi{}C. The Curie point of BaTi${\mathrm{O}}_{3}$ decreased linearly with inc…
Transition-metal spinels with magnetic ions solely on the octahedral sites have been the subject of many investigations. The properties of such spinels had always been found to be dominated by antiferromagnetic interactions. In this paper we describe the properties of a group of spinels in which ferromagnetic interact…
Abstract Polymers which contain conjugated bonds (polyenes) cannot be distinguished from polymers containing conjugated bonds (polyimines) by spectral means alone. A chemical means has been found for distinguishing between polyenes and polyimines. Polyenes can be hydrogenated with the aid of palladium supported on cha…
Optical nonlinearities due to conduction-band electrons have been observed in InAs, InSb, GaAs, and PbTe using 10.6-\ensuremath{\mu} (${\ensuremath{\omega}}_{1}$) and 9.6-\ensuremath{\mu} (${\ensuremath{\omega}}_{2}$) radiation from a $Q$-switched C${\mathrm{O}}_{2}$ laser. Difference frequencies ${\ensuremath{\omega}…
Received 4 October 1966DOI:https://doi.org/10.1103/PhysRevLett.17.1015©1966 American Physical Society
Potassium chloride crystals have been doped with ${\mathrm{Sm}}^{2+}$ ions to concentrations of 5\ifmmode\times\else\texttimes\fi{}${10}^{19}$ ${\mathrm{cm}}^{\ensuremath{-}3}$, resulting in identifiable ${\mathrm{Sm}}^{2+}$ absorption spectra. Heating of the doped crystals in K vapor produces no visible change in the…
Abstract The Plasticity Retention Index (PRI) has been developed as an objective test for the oxidizability of raw natural rubber and has recently been associated with the Standard Malaysian Rubber Scheme. Oxidizability as measured by PRI significantly affects behavior of rubber in the factory and in service performan…
The phenomenon of carbon deposition on specimen surfaces during electron-probe microanalysis has been studied using a stearate crystal for analysis. Contamination was found to build up at a rate which rapidly interfered with light element microanalysis and depended upon conditions prevailing in the specimen chamber of…
The first magnetocrystalline anisotropy constant of plastically deformed nickel single crystals was studied as a function of deformation. Contributions of specific types of imperfection, viz., interstitials, vacancies, and disclocations on the ``effective magnetic anisotropy constant'' K1′ were analyzed from the recov…
An irradiation program to evaluate BeO as a moderator or fuel matrix material in nuclear power reactors has been completed at the Oak Ridge National Laboratory. The primary objectives were: to establish the limits of stability of sintered BeO of various grain sizes and densities toward fast-neutrons and to determine m…
Abstract A new high‐temperature elastomer, SiB‐2, has been investigated by stress relaxation, modulus‐temperature, and volume‐‐temperature techniques. SiB‐2 was found to be more stable than a related elastomer, radiation‐cured silicone rubber, having about twice as long as a chemical relaxation time at 250°C. Possible…
It is proved that the modulus of the Fourier-transform of the magnetic anomaly of a two-dimensional magnetized body is determined by two parameters less than those determining the anomaly itself. This is true for any component of the field. A method is developed to calculate estimates of the Fourier-transform from a l…