Materials Literature
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The structural stability and electronic properties of the ternary intermetallic compounds NiSnM (M=Ti,Zr,Hf) and the closely related Heusler compounds ${\mathrm{Ni}}_{2}$SnM are discussed using the results of ab initio pseudopotential total-energy and band-structure calculations performed with a plane-wave basis set u…
Single crystals of the skutterudite ${\mathrm{CoSb}}_{3}$ exhibit large hole mobilities (up to 3000 ${\mathrm{cm}}^{2}$ ${\mathrm{V}}^{\mathrm{\ensuremath{-}}1}$ ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$ at room temperature), intrinsic lattice thermal conductivity down to 10 K, and pronounced phonon drag effects in th…
We report the successful synthesis of ${\mathrm{B}}_{\mathit{x}}$${\mathrm{C}}_{\mathit{y}}$${\mathrm{N}}_{\mathit{z}}$ nanotubes. Arc-discharge methods were used to produce stable nanotubule structures identified by high-resolution transmission-electron microscopy. Local electron-energy-loss spectroscopy of K-edge ab…
We have measured the dielectric relaxation times of the α process of phenyl salicylate (salol) covering 11 decades in frequency. Being representative for the class of low molecular weight organic glass forming materials, the highly resolved temperature dependence of the dynamics in salol does not follow a particular f…
The effects of thermal activation on the dislocation emission from an atomistic crack tip are discussed. Molecular dynamics simulations at different constant temperatures are carried out to investigate the thermal effects. The simulated results show that the processes of the partial dislocation generation and emission…
The alternating current conductivity of Li 0.5+0.5x Ge x Fe 2 O 4 (where x=0.0, 0.2, 0.3 and 0.5) has been studied as a function of frequency, whereby the conductivity showed a dispersion with respect to frequency. In the range of dispersion it was found that sigma ( omega ) alpha omega S , where S is a constant. At f…
The source characteristics of third-generation synchrotron radiation machines lead to enhanced possibilities for diffraction topographic techniques: real-time observations, high-resolution experiments, investigation of heavy or bulky materials using short wavelengths and the possibility of using large sample environme…
The elucidation of the structure of semiconductor multilayers can be adequately determined by X-ray methods but the interpretation is not always straightforward. In this paper we introduce the idea of full three-dimensional diffraction-space mapping to obtain information on the three-dimensional structure of imperfect…
X-ray projection reflection topography has been applied to a number of strongly absorbing crystals in order to find general rules for rendering dislocations visible. Single- and double-crystal schemes have been utilized. Considering direct images of dislocations and calculating the ratio of extinction to the absorptio…
Variations in the band structures of C60-polymers are studied, when pi-conjugation conditions are changed. We look at band structures in order to discuss a metal-insulator transition, using a semi-empirical model with the Su-Schrieffer-Heeger type electron-phonon interactions. We find that electronic structures change…
Self-diffusion coefficients of a series of polycyclic charged systems and their parent compounds were measured by using the PGSE NMR method. These data suggest that the dianions of naphthacene 2 and pyracylene 3 may exist as dimers with sandwich structure, just like the lithium salt of the tetraanion of corannulene 1.
The arrangement of charged and uncharged guests (N and two H2O molecules; see structure on the right) and their interaction in the cavity of the anion of the title compound 1 can be controlled by deliberately exchanging particles in the truncated cone outside the host (not shown), which resembles an ion channel. Since…
Abstract This book describes how Monte Carlo modeling methods can be applied to Electron Microscopy and Microanalysis. Computer programs for two basic types of Monte carlo simulation are developed from physical models of the electron scattering process; a Single Scattering program capable of high accuracy but requirin…
Abstract Reactive extrusion of polypropylene (PP)/natural rubber (NR) (90/10) blends was conducted in the presence of a peroxide [1,3‐bis( t ‐butylperoxy)benzene] and coagent (trimethylolpropanetriacrylate, TMPTA). Effects of peroxide and coagent content were studied in terms of melt index (MI), melt viscosity, morpho…
Abstract Introduction of amidoxime groups into cellulose substrate was investigated by reaction of cyano‐group‐containing celluloses such as cyanoethylcellulose (CE‐Cell) and acrylonitrilegrafted cellulose (G‐Cell) with hydroxylamine at 70°C in water medium (pH = 7.0). Dissolving pulp from softwood was used as the cel…
Correlations in low-frequency atomic displacements predicted by molecular dynamics simulations on the order of 1 ns are undersampled for the time scales currently accessible by the technique. This is shown with three different representations of the fluctuations in a macromolecule: the reciprocal space of crystallogra…
Analytical procedures are developed for a composite system consisting of shape memory alloy fibers within an elastic matrix subject to uniform temperature. Micromechanics for the calculation of the equivalent properties of the composite are prcscnted by extending the multi-cell model to incorporate shape memory alloy…
Ion transport mechanisms in Mg 2+ -stabilized Na + - beta ''-alumina were investigated by molecular dynamics simulations. Two compositions, different Mg 2+ distributions, and different system sizes were used in the temperature range from 200 K to 1700 K. The trajectory plots of Na + ions and the Na + -Na + radial dist…
We report optical second harmonic generation measurements in single crystal α-SiC of polytype 6H. The angular dependence of second harmonic intensity was consistent with two independent nonvanishing second order susceptibility components, as expected for a crystal with hexagonal symmetry. For the fundamental wavelengt…
Strong and stable blue photoluminescence (PL), visible to the naked eye under 0.4 μW of 300 nm and 2.7 μW of 370 nm excitation, has been observed for samples of Si clusters embedded in SiO2 matrices, prepared by rf co-sputtering followed by N2 annealing at 800 °C. Si K-edge extended x-ray absorption fine structure (EX…