Materials Literature
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We report measurements of the magnetic susceptibility, Knight shift, and nuclear spin-lattice relaxation rates in the pure compounds Au${\mathrm{Ga}}_{2}$ and Au${\mathrm{In}}_{2}$ and an alloy of nominal composition ${\mathrm{Au}}_{0.95}$${\mathrm{Pd}}_{0.05}$${\mathrm{Ga}}_{2}$. Measurements were made in both the so…
The kinetics of energy transfer from antimony sensitizer to manganese activator in fluorophosphate phosphors has been studied. The transfer mechanism is identified as an exchange interaction by a comparison of the manganese concentration dependence of experimental quantum yield and emission decay curves with theoretic…
A novel electro-optic effect has been observed in thin homeotropic nematic layers. Electrodes, such as a pair of parallel lines, are located on a planar surface in contact with the liquid. Deformation of the homeotropic ordering occurs when the applied field exceeds a threshold strength. Induced optical birefringence…
The qualitative features of the bulk and surface energy bands of ionic transition-metal perovskite crystals such as SrTi${\mathrm{O}}_{3}$, BaTi${\mathrm{O}}_{3}$, KTa${\mathrm{O}}_{3}$, and BaZr${\mathrm{O}}_{3}$ are discussed. The linear-combination-of-atom orbitals (LCAO) method is used in combination with a genera…
We consider classical transition-state theory of collinear atom-diatom reactions. There are (many) potential surfaces for which this theory is exact provided all trajectories with energy above some fixed value are disregarded; the energy cutoff of course depends on the surface. We develop a simple criterion for recogn…
The dielectric relaxation study of glass-forming liquids show the presence of two relaxation regions at temperatures above TQ. The low frequency relaxation is attributed to the cooperative rearrangement of molecules. The high frequency relaxation, which continues to exist in the glassy state, is suggested to arise fro…
The point-multipole model, together with the Sawatzky model for overlap effects, has been used to calculate the electric field gradient tensors at the two nonequivalent ferric sites in Ca 2 Fe 2 O 5 . Good agreement with Mossbauer results has been obtained if alpha D and alpha Q , which have been considered as variabl…
Normal incidence reflectivity spectra using polarized light have been measured with E perpendicular to c as well as E//c for the layer type crystals of transition metal dichalcogenides WS 2 , WSe 2 , alpha -MoTe 2 , NbS 2 and NbSe 2 at 78 K and 300 K. Reflectivity peaks observed in the spectra of two polarizations are…
The magnetization of single crystals of Eu, Sm, Nd, Pr, and Pr-Nd alloys has been measured in fields up to 37 T (370 kG). The results give new information on the magnetic properties of these metals. Of particular interest is a first-order transition from a nonmagnetic to a metamagnetic phase in double-hexagonal close-…
A method is described for the direct measurement of the shear-alignment angle in a nematic liquid crystal. Results of such measurements are reported for the nematic phases of three compounds: PAA ($p$, ${p}^{\ensuremath{'}}$-azoxydianisole), MBBA ($p$-methoxybenzylidene-${p}^{\ensuremath{'}}\ensuremath{-}n$-butylanili…
An x-ray photoemission study of evaporated Al films has been performed in ultrahigh vacuum. The striking similarity of the valence-band spectrum with computed density of states allows a straightforward interpretation of the results. Core level spectra reveal structures which can be attributed to either inelastically s…
Abstract The behaviour of the ½a<111> screw dislocation core in the presence of an external shear stress on {110} planes has been studied for a variety of effective interionic potentials, each representing a stable b. c. c. lattice. The distortion and motion of the core are described using the concept of…
Phonon pulse propagation has been studied in fused silica at frequencies between 0.4 and 2.0 GHz for temperatures as low as 0.1 K. An increase in attenuation, observed as the incident acoustic intensity is decreased, is attributed to resonant scattering by two-level "tunneling states" intrinsic to glasses.
Reactivity and compatibility studies were carried out on some vanadium base alloys with ceramic fuel materials. The vanadium base alloys studied were V-20%Ti, V-15%Ti-7.5%Cr and V-5%Cr. The fuel materials with which these alloys were put in contact were UC, UN, (U, Ce)N and (U,Ce)(C,N). Experiments were carried out at…
Abstract Cotton sateen fabric was found to react with the 1 : 2 adduct of phosphorus trichloride and N,N‐dimethylformamide (DMF) in DMF or DMF—chloroform solutions at room temperature. During this reaction, the fabric acquired flame resistance. The introduction of as little as 1.2% phospohorus and 0.4% nitrogen, achie…
Silicone rubber rods covered by a polyester fiber mesh were implanted adjacent to either a femoral or carotid artery in 13 dogs. The rods were pulled out eight to ten weeks later and a segment of the carotid or femoral artery was excised and replaced by the newly formed tissue tube. Angiographic studies confirmed the…
Paramagnetic susceptibilities, χ i ( i = a , b , c ) of single crystals of rare-earth orthoferrites RFeO 3 (R=Nd, Sm, Gd, Dy, Er, Yb and Y) were measured along the a , b and c axes at room temperature and 77 K. The main parts of the effective magnetic moments µ eff, i 's were found to originate from rare-earth ions. A…
The copper-rich portion of the copper–manganese–tin system was investigated by X-ray diffraction, electron microprobe, and magnetometric techniques. A model for the ordering taking place in the β phase was established. Two low-temperature phases for the alloy composition Cu2MnSn were identified, and the existence of t…
Adsorption uf particulate solids and synthetic soil on cellulose and synthetic fabrics has been studied by a dynamic method involving high speed rotation of the solid and the substrate in a closed chamber. The results confirm that adhesion, and not mechanical entrapment, is the dominant soiling mechanism. Adsorption o…
A review of application circuits for two-terminal amorphous semiconductor switching devices encompassing both the threshold and memory switches is presented, including brief discussions of device electrical and structural characteristics. The most useful electrical properties of these devices are seen to be the thresh…