Materials Literature
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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…
Keith Marshall, David Sixsmith; The flow properties of microcrystalline cellulose powders, Journal of Pharmacy and Pharmacology, Volume 28, Issue 10, 1 Oct
The swelling of metals during irradiation is due to the preferential drift of interstitials to dislocations thus allowing vacancies to condense in excess of interstitials at voids. Previously the dislocation preference for interstitials has been calculated from an isolated dislocation model, here the effect of the com…
The numerical determination of current and potential distributions has been performed for plating corrosion systems, where failure to coat a small area leads to corrosion at the pinhole. The distributions depend on characteristic parameters for the disk anode and surrounding plane cathode and reveal that each of the e…
Absorption measurements on amorphous selenium, arsenic and arsenic triselenide have been performed using synchrotron radiation. The results obtained reveal the importance of many body effects, matrix elements, and site of the initial state in the interpretation of optical data corresponding to transitions from core le…
Abstract SrNiO 2 ‐Einkristalle wurden bei hohen Temperaturen unter O 2 ‐Druck dargestellt. SrNiO 2 ist isotyp mit SrCuO 2 (Raumgruppe D —Cmcm, a = 3,581, b = 16,362, c = 3,915 Å) Die kristallchemische Verwandtschaft zum K 2 NiF 4 ‐Typ wird diskutiert.
The effect of cobalt substitutions in manganese zinc ferro ferrites for inductor applications is discussed. Permeability-temperature curves are presented over the range -50 degrees C to 200 degrees C for compositions where the cobalt level is varied between 0 and 0.010 per formula unit, the Mn/Zn ratio and Fe 2+ level…
Abstract The Mössbauer spectra of graphite–FeCl3 and graphite–FeCl3–AlCl3 compounds with varying FeCl3/AlCl3ratios were measured. At 298 K, the isomer shift of the Fe3+ peak of FeCl3 intercalated in the graphite–FeCl3 compounds was larger than that of pure anhydrous FeCl3, and two sets of Fe2+ quadrupole doublets appe…