Materials Literature
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The structure, cation distribution, and cation valencies of the CuxMn3−xO4 spinel system are investigated by means of some selected experiments on specimens of this spinel system and some similar Cu and Mn containing spinels. Dilatation measurements reveal two important cation migration processes, namely the cation ex…
Structural and dielectric studies have been performed on CsH2PO4 for scrutinizing the validity of the previously reported structure. It is found that the symmetry in the paraelectric state is not orthorhombic as previously assumed but monoclinic with the space group of C. The net configuration of hydrogen bond and the…
A generalisation of Mott's model of an amorphous solid is used to investigate the characteristics of carrier transport by hopping in an extended temperature range. It is shown that three types of behaviour can be expected, the Mott T−-1/4 variable-range hopping at low temperatures, nearest-neighbour hopping at high te…
The molar hat capacity of GeTe, SnTe, and Pbte have been measured by the heat-pulse method from 0.9 to 60 K. No conclusive evidence was found for th effect o the soft TO phonon modes known to be presen in these mateials. An anomalous excess heat capacity previously reported near 3 K for GeTe was not confirmed. A deail…
We consider a set of dipole impurities randomly distributed in a nonpolar medium where the only interaction between the impurities is the dipole-dipole interaction. The dipoles are assumed to be oriented in the six equivalent (1,0,0) directions found experimentally to exist when O${\mathrm{H}}^{\ensuremath{-}}$ impuri…
The intensities of the electric dipole transitions of Ho3+ in three oxide glasses have been obtained from the absorption spectra in the visible and ir for tellurite glasses, and in the uv, visible, and ir parts of the spectrum for calibo and phosphate glasses. From the experimental values of the oscillator strengths a…
Optical constants were obtained by Kramers-Kronig analysis of normal-incidence reflectivities of Ni, Fe, concentrated FeNi alloys, and ordered and disordered ${\mathrm{Ni}}_{3}$Fe. Measurements were made from 2 to 27 eV and extended to 35 eV in Ni. Specimens were either thin evaporated films or bulk specimens that wer…
Detailed measurements and line-shape fits of the combined LO- and TO-phonon assisted electron-hole condensate luminescence lines from laser-excited, high-purity Si are reported in the temperature range from 2.2 to 13.0\ifmmode^\circ\else\textdegree\fi{}K. These data permit a determination of the liquid density $n$, ch…
Infrared studies of single crystals and thin films of the one-dimensional organic metal tetrathiofulvalene-tetracyanoquinodimethane (TTF-TCNQ) are presented. The frequency-dependent conductivity, ${\ensuremath{\sigma}}_{1}(\ensuremath{\omega})$, and dielectric function, ${\ensuremath{\epsilon}}_{1}(\ensuremath{\omega}…
Reflectivity and wavelength-modulated reflectivity measurements on GaSe and $\mathrm{Ga}{\mathrm{S}}_{x}{\mathrm{Se}}_{1\ensuremath{-}x}$ mixed crystals are presented for energies ranging from 3 to 6 eV. Additional electroreflectance measurements are used to investigate the excitonic character of the structure at 3.4…
The geometry of stationary or mobile metallic and semiconducting domain configurations and their formation during the switching of a VO 2 single crystal are discussed. It is shown that the motion of narrow semiconducting domains in the sense of the electric current is driven by the Peltier effect at the two oppositely…
DC magnetization measurements at 4.2K in applied fields up to 340 kG are reported. The smooth behaviour of the magnetization curves confirms that the anisotropy may be attributed to the octahedral site Mn ions.
Mossbauer and magnetization measurements have been carried out in Co 2 -Z compound. The Mossbauer data have been correlated to measurements of magnetization and anisotropy constants. The temperature dependence of the second-order anisotropy constant K 2 turn out to be of single-ion origin and essentially determined by…
The thermal and electrical resistivity and Seebeck coefficient of heavily doped, pressure-sintered germanium-silicon alloy specimens have been measured in the temperature range 300-1200K. The thermal resistivity was considerably in excess of that for corresponding crystalline samples at temperatures below that of the…
The change in the band gap of a semiconductor due to high doping is considered in the limit where the free carriers form a degenerate gas. In contrast to previous treatments, the effect of the change in the electron interaction on the whole band structure is considered within a self energy framework so that the differ…
The electrical resistivities of single crystals of LaB 6 and ReO 3 were measured in the temperature ranges of 4.2-360K and 4.2-300K, respectively. The residual resistance ratio of LaB 6 was 450 and that of ReO 3 was 90. The resistivity value of LaB 6 at 300K is 8.90*10 -6 Omega cm and for ReO 3 , 10.5*10 -6 Omega cm.…
Abstract A comprehensive method is given for describing in reduced terms pendent drops, emergent bubbles, sessile drops and captive bubbles of a fluid α within a fluid β as figures produced by revolution of their meridian curves (X, Z). Boundary conditions at a solid surface are: (a) with a constant contact radius XƟ;…
Long-wavelength (submillimeter plus millimeter) photoconductivity measurements in doped germanium have been performed under uniaxial compressive stress along the [111] crystal direction. The electron affinity estimated from newly observed spectra is smaller than that in a previous measurement without stress and is con…
$1T\ensuremath{-}{M}_{x}{\mathrm{Ta}}_{1\ensuremath{-}x}{\mathrm{S}}_{2}$ or $1T\ensuremath{-}{M}_{x}{\mathrm{Ta}}_{1\ensuremath{-}x}{\mathrm{Se}}_{2}$ with $M=\mathrm{F}\mathrm{e},\phantom{\rule{0ex}{0ex}}\mathrm{C}\mathrm{o},\phantom{\rule{0ex}{0ex}}\mathrm{o}\mathrm{r}\phantom{\rule{0ex}{0ex}}\mathrm{N}\mathrm{i}$…
The dynamics of the helix-coil transition of single-stranded poly(C) (polyribocytidylate) and CpC (cytidyly(3'-5')cytosine) was investigated by an improved cable temperature-jump technique. The single-strand relaxation was characterized by following the ultraviolet (uv) absorbance changes at 248 and 280 nm. Poly(C) an…