Materials Literature
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A method is developed to calculate the parameters of a pair potential function with three adjustable parameters. It uses crystalline state properties at any given temperature. As an example, parameters of the Morse potential are calculated for a number of metals using physical properties at room temperature. Elastic c…
The ratio n of cross-sections for inelastic and elastic scattering of 80 keV electrons is measured for thin solid films of the elements Be, C, Al, As, and Sn. The values obtained are in reasonable agreement with theoretical predictions of Lenz and Burge and Smith. Measurements of n are also made for diphenyl anthracen…
Phase anarysis oj boron in steel has been made to establish a practical method Jor the determination oj the content oj "effective boron", i.e., boron which is effective in improving the hardmability oj steel, yielding the Jollowing results:(1) Electrorytic dissolution and iodine-methanol dissolution are reliable and r…
It was found that sintered alloys having a composition of approximately z=8 in Sm(Co0.85Fe0.05Cu0.10)z exhibit a high coercive force on the order of 10 kOe, for 5–10-μm average grain size. Magnetization and demagnetization curves showed that the coercive force is controlled by a nucleation process. Attempts were made…
The anisotropy of the electron-phonon collision frequency on the Fermi surface of silver has been determined from the temperature dependence of radio-frequency-size-effect (RFSE) line amplitudes. In all cases when ln $A$ is plotted vs ${T}^{3}$ the expected linear relationship is observed. The average collision freque…
We present our acousto-optic measurements of the photoelastic tensor of the cuprous halides, CuCl, CuBr, and CuI. The data include the magnitudes and signs of the coefficients and their optical wavelength dependence. Several distinct trends are observed as a function of ionicity both within the halides and in the isoe…
An electron paramagnetic resonance study was made of Mn2+, Fe3+, and Cu2+ doped into the glass systems BaO–B2O3–Al2O3 and CaO–B2O3–Al2O3. The spectra of the manganese doped samples exhibited a barely resolved Mn2+ hyperfine pattern at g=2 and in some cases low field lines at g∼3 and g∼5. The concentration dependence o…
First- and second-order resonant Raman scattering from ${\mathrm{Mg}}_{2}$Si,${\mathrm{Mg}}_{2}$Ge, and ${\mathrm{Mg}}_{2}$Sn were measured with laser frequencies covering the ${E}_{0}$ and ${E}_{1}$ gaps for ${\mathrm{Mg}}_{2}$Si, the ${E}_{1}$ gap for ${\mathrm{Mg}}_{2}$Ge, and the ${E}_{1}$ and $X$ gaps for ${\math…
In this paper, the adiabatic relaxation theory is applied to investigate the origin of rare-earth fluorescence quenching involving multiphonon transitions. The energy level schemes for BaCl2:Sm2+ and BaBr2:Sm2+ have been obtained from the observed fluorescence spectra. The phonon cutoff frequencies, 210 and 140 cm−1 f…
The temperature-dependent Debye-Waller factors for SmS, GdS, ${\mathrm{Eu}}_{0.8}$${\mathrm{Y}}_{0.2}$S, and ${\mathrm{Sm}}_{0.7}$${\mathrm{Y}}_{0.3}$S have been measured by single-crystal x-ray diffraction technique. From these data, we have determined the mean-square displacements $〈{u}_{i}^{2}(T)〉$ for the sulfur a…
Experimental results are presented on the interesting $2{a}_{0}$ by $2{c}_{0}$ superlattice which forms in ${\mathrm{Ti}}_{1+x}{\mathrm{Se}}_{2}$ at low temperature. A second-order phase transition has been found at ${T}_{c}\ensuremath{\cong}150$\ifmmode^\circ\else\textdegree\fi{}K in crystals grown by iodine vapor tr…
Man-made boron-doped diamonds have been iradiated with energetic electrons. The effect of the energy of the irradiations, performed around 15\ifmmode^\circ\else\textdegree\fi{}K, upon the conductivity measured at 12\ifmmode^\circ\else\textdegree\fi{}K has been studied. The comparison between the variations, with the e…
The self-diffusion coefficient of water has been measured by the steady-gradient spin-echo method at pressures up to 2380 bar and temperatures between 2 and −20°C in the stable liquid range using both strengthened glass and beryllium–copper pressure vessels. At low temperatures and high pressures the diffusion coeffic…
The first-order Raman spectrum of cubic zinc metaborate has been measured at room temperature, and the number of q=0 phonon frequencies found exceeds the group theoretical prediction by one. The additional band appears as an interference feature at 122.5 cm -1 and is thought to be attributable to some impurity introdu…
The dynamics of the phase transition in SrTiO 3 (T c approximately 105K) is complicated by the presence of a central mode in the scattering at the R point of the cubic Brillouin zone in addition to the expected soft-mode scattering. Experiments using Mossbauer gamma rays are reported in which 'elastic' scattering with…
Reports uniaxial stress measurements on the 30307 cm -1 absorption line of the A aggregates of nitrogen in diamond. The A aggregates are shown to be trigonal. This result together with published data suggests that an A aggregate is a pair of nitrogen atoms substituting for two carbon atoms.
The photosynthetic light-harvesting complex, peridinin-chlorophyll a-protein, was isolated from several marine dinoflagellates including Glenodinium sp. by Sephadex and ion-exchange chromatography. The carotenoid (peridinin)-chlorophyll a ratio in the complex is estimated to be 4:1. The fluorescence excitation spectru…
American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. Abstract The clay mineral sepiolite has been under investigation since 1972 by our laboratories for possible use in drilling fluids. This paper reviews the work done on this clay mineral in an effort to obtain a drilling fluid capable of withst…
Samples of annealed and severely cold-rolled vanadium were bombarded at room temperature with 150-keV H+ ions at fluxes from 1.2×1015 to 1.2×1016 H+/cm2 sec to doses of from 3.6×1017 to 3.2×1019 H+/cm2. All samples irradiated to doses greater than 1.1×1019 H+/cm2 exhibited blistering in spite of the fact that temperat…
Extensive electrical and thermal studies on transitions in (CrxV1-x)2O3, 0 ⩽ x ⩽ 0.03, and in (TixV1-x)2O3, 0 ⩽ x ⩽ 0.06, have been undertaken. An increase in Cr-doping (0 ⩽ x ⩽ 0.018) raises the temperature of the low-temperature transition and elevates the resistivity of the metallic phase ; it first sharpens and la…