Materials Literature
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X-ray photoelectron spectroscopy has been used to investigate the atomic species, and their bonding, within the conductive polymer polyaniline (PANi). PANi was grown electrochemically using HCl as the electrolyte ion and all three of PANi's oxidation states were investigated. Measurements of the C 1s, N 1s, O 1s and C…
X-ray scattering studies of (N(CH 3 ) 4 ) 2 MnCl 4 under pressure reveal strong indications of the existence of several new commensurate phases with long periods. The wave vectors of these phases are found to constitute a set of the Farey-tree series. Structure branching and other features in the observed P-T phase di…
We have studied the coarsening dynamics of line defects in the uniaxial nematic liquid crystal 4-cyano-4'-n-pentylbiphenyl, subjected to a rapid pressure jump from the isotropic to the nematic phase. At late times, the density of disclination lines \ensuremath{\rho} is expected to scale with time as \ensuremath{\rho}\…
An overall survey of the structural and magnetic features of the La 2 NiO 4+ delta system is presented as a result of neutron diffraction experiments. The stoichiometric compound ( delta =0) presents two structural phase transitions. At T 0 approximately=770 K, La 2 NiO 4 transforms from tetragonal (I4/mmm) to orthorh…
For the first time, the fabrication of a periodically reversed domain structure for LiNbO3 has been achieved at room temperature. The domain boundary is perpendicular to the positive c-face and is very deep which is advantageous for quasiphasematching SHG.
A semiclassical interatomic potential for carbon is discussed which is based on the proximity cell (the Wigner-Seitz cell) around each atom. It introduces three internal degrees of freedom per atom, representing the magnitude and direction of the p orbital that is not involved in sp hybridization. Its direct interpola…
By means of hyper-Raman scattering, a silent soft phonon was observed in \ensuremath{\beta}-quartz for the first time. The soft phonon was found to become underdamped at high temperatures. Both the square of the frequency ${\mathrm{\ensuremath{\omega}}}_{0}^{2}$ and the integrated intensity ${\mathit{I}}_{0}$ of the s…
Ceramic layer epitaxy, defined as the epitaxial growth of ceramic thin films with thicknesses regulated on an atomic scale, was verified by a new method using pulsed laser deposition in ultrahigh vacuum (UHV). The intensity oscillation of reflection high-energy electron diffraction (RHEED) was observed in an ArF excim…
We have discovered that the rare-earth–iron intermetallics of the type RTiFe11 can absorb moderate quantities of nitrogen at 500 °C, giving the approximate composition RTiFe11N0.5 at 1 atm. X-ray diffraction showed that the tetragonal structure (I4/mmm) is retained but that the unit cell volume is slightly increased.…
Abstract Hydrocarbon‐soluble oligomers were prepared by the acid‐catalyzed condensation of alkylanilines with formaldehyde. Highest molecular weight oligomers (MW ∼ 6000) were obtained from alkylanilines prepared by the Friedel‐Crafts alkylation of aniline with α‐olefins. By NMR, it was shown that the oligomers contai…
Abstract 1,2,4,5‐Benzenetetra acyl chloride (BTAC) was prepared from pyromellitic anhydride and phosphoric chloride. The behavior in interfacial polycondensation of 4,4′‐methylene dianiline (MDA) or ethylene diamine (EDA) in water with BTAC in dichloromethane with tetrabutyl ammonium chloride (TBAC) as the catalyst wa…
Abstract The fluorinated surface layer of poly(4‐methyl‐1‐pentene) membranes exposed to a dilute stream of fluorine gas has been characterized with X‐ray photoelectron spectroscopy. The concentration and profile of reacted fluorine as a function of exposure time is determined. A computer routine was employed to deconv…
The structure and dynamics of three-dimensional foams are probed quantitatively by exploiting the strong multiple scattering of light that gives foams their familiar white color. Approximating the propagation of light as a diffusion process, transmission measurements provide a direct probe of the average bubble size.…
Abstract The sodium and europium cryptates of the new macrobicyclic ligands 2 and 3 incorporating the 2,2′‐bipyri dine 1,1′‐dioxide and 3,3′‐biisoquinoline 2,2′‐dioxide units, respectively, have been prepared. The Eu III complexes present characteristic 1 H‐NMR spectra, showing large shifts, and are strongly luminesce…
This review contains the results of theoretical and experimental investigations of nonlinear electromagnetic phenomena associated with the effect of the magnetic field of a radio wave on the dynamics of electron movement, and hence on the conductivity of metals. Such a magnetodynamic mechanism of nonlinearity is most…
The objective of this activity is to measure the lithium vaporization from lithium oxide breeder material under differing temperature and moisture partial pressure conditions. Lithium ceramics are being investigated for use as tritium breeding materials. The lithium is readily converted to tritium after reacting with…
The synthesis of a linear polymer having a tertiary amino group in a part of the main chain has been attempted by several methods. However, it was difficult for the linear polyamine to form because of the complicated reaction of the amino group. In the polymerization of weakly basic cyclic amines, e.g., 1-cyanoethylaz…
Abstract Solid‐state extrusion of crystalline polymers is a well‐known technique to produce monoaxial orientation in filaments and films. This is essentially achieved by extruding or drawing the polymer through a convergent die at temperatures below its melting point. Biaxial orientation in die drawing processes has b…
The series of liquid crystals in which the rigid part is constituted by heteroaromatic cation (thiopyrylium, 1- 2 -dithiolium) have been synthesized. The nature of the mesophases depends on the number of flexible substituants grafted on the cationic units. Lamellar (SA) mesophases are obtained with two or three chains…
The texturalcentric model of non-attribute-based visual and tactile response to textural fabric surfaces was used to elicit definitive qualities or dimensions of textural fabric surfaces. Multidimensional scaling analysis permitted subjects to provide numeric judgements of fabrics rather than using words with individu…