Materials Literature
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The electrical, thermoelectric, magnetic, and crystallographic properties of Ga-doped VO2 single crystals V1−xGaxO2 (0 ≦ x ≦ 0.013) are investigated. By Ga-doping the transition temperature of the semiconductor-metal transition of VO2 is elevated and the resistivity discontinuity is little increased. The T–x-phase dia…
A method of calculating the anisotropy of Poisson's ratio is applied to trigonal and tetragonal crystals in the literature. The method of calculation is extended to hexagonal crystals. The results are illustrated by reference to Tl and Cd.
YOHCO3, or thorhombic, P212~2~; a = 4.809 (1), b=6 .957 (l), c=8 .466 (1) A; Z = 4 , de= 3.89 g c m -a. The final R for 737 reflections was 0.0518. The carbonate-group distances and angles are C-O(1) 1.288 (9), C-O(2) 1.279 (9), C-O(3) 1-287 (8) A, O(1)-C-O(2) 122.8 (7), O(1)-C-O(3) 118-7 (6), and O(2)-C-O(3) 1183 (7)…
Magnetic susceptibility and nuclear magnetic resonance of Cu and Cl nuclei have been studied in monocrystals of [C6H5(CH2)nNH3]2CuCl4 with n=1,2,3 below 4.2 K. These compounds are two-dimensional ferromagnets with a dominant XY-type anisotropy. For the compound with n=1, the Ising anisotropy is extremely small. The NM…
Results of the standard dynamical theory of x-ray diffraction by Bragg planes parallel to a crystal surface are reproduced using Abel\'es's 2 \ifmmode\times\else\texttimes\fi{} 2 matrix method for finding reflection and transmission by layered isotropic structures. In addition to giving a somewhat different insight in…
Important structural features of the two low-temperature phases of ${\mathrm{RbAg}}_{4}$${\mathrm{I}}_{5}$, designated $\ensuremath{\beta}$,$\ensuremath{\gamma}$ in order of decreasing temperature, have been determined, even though the precise structure of the $\ensuremath{\gamma}$ phase is unattainable because of the…
We have extended previous measurements of electrical resistivity and Hall coefficient of single crystals of cubic ${\mathrm{Na}}_{x}\mathrm{W}{\mathrm{O}}_{3}$ to a wider range of values of $x$ and of sample temperature. These new data cover a temperature range from 4.2 to 300 K, and a range of $x$ values from $x=0.22…
Energy-loss experiments with 50-keV electrons on thin polycrystalline films of Al and In yielded data for the surface plasmon dispersion up to ${k}_{\ensuremath{\parallel}}=0.47 \mathrm{and} 0.42$ ${\mathrm{\AA{}}}^{\ensuremath{-}1}$, respectively. The wave-vector dependence of the surface plasmon frequency of Al show…
By ’’photodoping’’ with silver, chalcogenide glasses become almost insoluble in alkaline solutions. This letter examines the applicability of this effect to silicon microfabrication technology. Suitable processing techniques and exposure characteristics are investigated. It is shown that the (Ag) -Se-Ge glass system c…
An interaction between chiral molecules is derived in terms of the orientations of their long molecular principal axes. In analogy with Maier–Saupe and Goossens the derivation is based on the electric multipole expansion. The molecules are assumed to behave as if they were cylindrically symmetric, i.e., the system is…
The Prigogine–Defay ratio, Π≡ΔCp Δκ/TV (Δα)2, has been derived for systems whose states need to be specified in terms of a number of order parameters z by considering the conditions of tangency of the equilibrium free energy surface and the free energy surface for constant values of the order parameters. It is shown t…
We describe in detail a new method for solving the coupled linear differential equations which appear in the theoretical statement of many types of scattering phenomena. Combining the speed advantage of propagation methods with the inherent stability of R-matrix methods, this method is fast and is unaffected by expone…
Some aspects of phase transition behavior have been studied for a classical system of particles which interact in pairs via repelling Gaussian potentials. In a specific low-temperature, low-density limit, this model acts as though it were composed of rigid spheres. Study of lattice sums suggests that at T=0, a fcc cry…
Neutron-diffraction studies of ${\mathrm{TiSe}}_{2}$ show that a second-order structural phase transition occurs at ${T}_{0}=202$ K involving transverse atomic displacements with wave vector $\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}}=(\frac{1}{2},0,\frac{1}{2})$. The electronic transport properties of the most n…
The spectra of ejected electrons following the excitation or ionization by 2 keV electrons in the outermost np shell of Ca (n=3) and Sr (n=4) have been measured with high resolution. Binding energies of the np 1/2 and np 3/2 electrons as well as the excitation energies of np 5 (n+1)s 2 nd 1 P levels of Ca and Sr have…
Rates of linear crystal growth have been measured for diopside and anorthite growing from their own melts by using a microscope heating stage. Rates were obtained for undercoolings of as little as 13°C. The rates are higher for diopside than for anorthite. Maximum growth rates observed are 1.5×10−2 cm/s (ΔT = 194°C) f…
Substrate core chemical shifts upon chemisorption of oxygen on aluminum are observed using variable-excitation-energy photoelectron spectroscopy. At low exposures a unique intermediate oxidation state evolves where the $\mathrm{Al} 2p$ level is shifted by only 1.3 eV toward higher binding energy as compared to the 2.6…
High-angle x-ray diffraction provides direct evidence that amianthoid change, occurring during aging of costal cartilage, corresponds to a transformation from an isotropic to a marked anisotropic distribution of collagen fibrils. Low-angle x-ray diffraction and electron microscopy show that the fibrils have the custom…
Formal expressions are derived for the effective thermal conductivity K ij of randomly dispersed suspensions undergoing shear. These are then evaluated for the cases of dilute suspensions of cylinders and of spheres when the bulk motion is a simple shear, the Péclet number Pe is large, and the particle Reynolds number…
Abstract The crystal structure of (1,1′‐ferrocenediyl)diphenylsilane has been determined from analysis of photographic X‐ray data. The crystal system is orthorhombic, a = 14.18(2), b = 12.54(2), c = 9.28(1) Å, space group P nma with four formula units. The molecule has crystallographic m (C s ) symmetry with atoms Fe…