Materials Literature
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It is shown that the local spin-density approximation describes well electronic structures of perovskite $\mathrm{La}M{\mathrm{O}}_{3}$ ( $M\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}$ Mn, Fe, Co, Ni) for the ground-state and single-electron excited-state properties. Inclusion of details of crystal structures…
We present a general scheme for the computation of the time dependent (TD) quadratic susceptibility ($χ^{(2)}$) of an extended insulator obtained by applying the `$2n+1$' theorem to the action functional as defined in TD density functional theory. The resulting expression for $χ^{(2)}$ includes self-consistent local-f…
Cubic structured CdS, CdSe, and CdTe, II–VI semiconductor nanoparticles have been synthesized using aqueous solution precipitation at room temperature. The ‘‘as-prepared’’ particles have a size of about 30 Å. Thermal annealing causes (a) an increase in particle size; (b) a structural transition from the cubic to the b…
We present results of temperature and magnetic field dependent resistivity ρ(H,T) and bulk magnetization M(H,T) measurements on post-annealed La0.7Ca0.3MnO3 thin films that were grown via pulsed-laser deposition. Both the resistivity and the anomalously large negative magnetoresistance peak near the ferromagnetic orde…
We propose a heterogeneous reaction-diffusion model for the hydration and setting of cement. The model is based on diffusional ion transport and on cement specific chemical dissolution/precipitation reactions under spatial heterogeneous solid/liquid conditions. We simulate the spatial and temporal evolution of precipi…
An extension of the evolution strategy for mixed-integer optimizationproblems is introduced. The resulting generalized evolution strategy is applied to the problem of optical multilayer coating design and the results are compared with results obtained by standard methods. The generalized evolution strategy as a synthe…
This paper explains the origin of the ferroelectric instability in LiNbO3 and LiTaO3 and compares the electronic structures and energetics of the two materials.
Resonant tunneling through semimetallic ErAs quantum wells embedded in GaAs structures with AlAs barriers was recently found to exhibit an intriguing behavior in magnetic fields which is explained in terms of tunneling selection rules and the spin-polarized band structure including spin-orbit coupling.
The band structures of 6H and 4H SiC calculated by means of the FP-LMTO method are used to determine the effective mass tensors for their conduction-band minima. The results are shown to be consistent with recent optically detected cyclotron resonance measurements and predict an unusual band filling dependence for 6H-…
A new method to obtain a local parameterization for the exchange term in the many--body electronic problem is presented. The approach amounts to the introduction of a coordinate dependent electron effective mass. Numerical results for metallic clusters in the jellium model are compared with other standard methods.
The results of study on dynamic dielectric properties of some H-bonded crystals are presented. It is shown that relaxational soft modes are responsible for the ferroelectric phase transition in RbD2PO4, PbHPO4 and NH4HSeO4 and their contribution accounts for the static permittivity. Glass-like dielectric relaxation wi…
Abstract The electromic behavior of polyaniline‐poly(sodium acrylate) composite films (CPAn‐PAcNa) combined with a polycation bound to the disulfonated bathophenathroline ligand‐Fe complex (QDM‐BPDS‐Fe) was investigated in a LiClO 4 CH 3 CN non‐aqueous aprotic solution. The combination was achieved by chemial deposit…
Low-frequency Raman scattering spectra of potassium nitrate, KNO3 are observed as a function of temperature in a range from room temperature up to 130 K above the melting point Tm (606 K), including its order-disorder phase transition point at 403 K (Tc ). A central peak grows drastically with increasing temperature b…
The solid phases which appear when heating crystalline bis n-decyl and n-dodecyl ammonium tetra-chlorozincates (C10Zn and C12Zn for short) were studied using differential scanning calorimetry, X-ray diffraction and infrared and Raman spectroscopies. The unit-cell parameters of the different phases were determined. For…
We report the effects of matrix impedance on the electrical and optical properties of polymer dispersed liquid crystal (PDLC) samples. It was found that the impedance of a PDLC sample is a function of the applied dc bias and the frequency of the superimposed ac perturbation signal. Using the Randles equivalent circuit…
Recombinant human adenovirus serotype 2 proteinase (both native and selenomethionine-substituted) has been crystallized in the presence of the serotype 12, 11-residue peptide cofactor. The crystals (space group P3(1)21 or P3(2)21, one molecule per asymmetric unit, a = b = 41.3 angstrum, c = 197.0 angstrum) grew in sol…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMorphological Aspects of Secondary Crystallization in Poly(ether-ester) Multiblock CopolymersR. A. Phillips and S. L. CooperCite this: Macromolecules 1995, 28, 17, 5734–5744Publication Date (Print):August 1, 1995Publication History Published online1 May 2002Published inissue…
Abstract The electron spin resonance parameters of the Tl and Pb dimer centers produced by electron trapping at pairs of neighboring Tl + or Pb 2+ impurity ions in alkali chlorides are reanalyzed. The analysis which uses a consistent set of molecular parameters is based on the molecular modcl previously employed to de…
The mechanism governing oxygen transport in the vicinity of the growth interface with varying rates of crystal rotation was investigated both experimentally and computationally. Rotation induces a sweeping flow out of high oxygen content melt contributing to uniform radial oxygen concentration. At low rates of rotatio…
Abstract Sb 4 (P 2 Se 6 ) 3 und Bi 4 (P 2 Se 6 ) 3 können über eine chemische Transportreaktion mit Iod aus den Elementen dargestellt werden. Die Verbindungen kristallisieren isotyp in der monoklinen Raumgruppe P2 1 /n (Nr. 14) mit den Gitterparametern a = 2 077,7(4) pm, b = 749,35(5) pm, c = 949,49(8) pm, β = 91,25(1…