Materials Literature
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We present a local orbital approach to the evaluation of the on-site repulsion energy $U$ for use in the $\mathrm{LDA}+U$ method of Anisimov and co-workers. Our objectives are to make the method more firmly based, to concentrate primarily on ground-state properties rather than spectra, and to test the method in cases…
This paper reviews x-ray photoelectron spectroscopy studies on carbon nitride (CN) and reports on results obtained from CN thin films prepared by mass selected ion-beam deposition. The core-level spectra of samples deposited at room temperature show that nitrogen is incorporated into the amorphous network in two diffe…
Lattice thermal conductivity of a quantum well limited by umklapp, impurity, and boundary scattering was investigated theoretically by taking into account dispersion of confined acoustic-phonon modes. We show that strong modification of phonon group velocities due to spatial confinement leads to a significant increase…
In a self-consistent Born approximation, the density of states and the conductivity are calculated in a two-dimensional graphite sheet in magnetic fields. Two different cases of scatterers are considered, the short-range case where the range is smaller than the lattice constant and the long-range case where it is comp…
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” opt…
The problem of phonon scattering by grain boundaries is studied within the wedge disclination dipole (WDD) model. It is shown that a specific q-dependence of the phonon mean free path for biaxial WDD results in a low-temperature crossover of the thermal conductivity, $κ$. The obtained results allow to explain the expe…
Using spin-density functional theory we investigated various possible structures of the hematite (0001) surface. Depending on the ambient oxygen partial pressure, two geometries are found to be particularly stable under thermal equilibrium: one being terminated by iron and the other by oxygen. Both exhibit huge surfac…
We present ab initio total energy and stress calculations for the unreconstructed and (2x1)-missing-row reconstructed Ir (110) and Rh (110) surfaces. We use a model based on ab initio results to show that the (Nx1) reconstruction is a faceting transition to a long-wavelength--corrugated (111)-like surface, and find th…
<div class="htmlview paragraph">Thermal engineering has long been left out of the concurrent engineering environment dominated by CAD (computer aided design) and FEM (finite element method) software. Current tools attempt to force the thermal design process into an environment primarily created to support struct…
The thickness and surface roughness of diamond films grown on a Ti–6Al–4V alloy in a microwave plasma reactor was measured in situ using optical pyrometry. The growing film results in oscillations of the apparent temperature with time, which can be explained by interference effects caused by reflections from the film/…
Expression of the Drosophila cell adhesion molecule neuroglian in S2 cells leads to cell aggregation and the intracellular recruitment of ankyrin to cell contact sites. We localized the region of neuroglian that interacts with ankyrin and investigated the mechanism that limits this interaction to cell contact sites. Y…
Polymer-dispersed liquid crystal (PDLC) with macroscopically uniaxial molecular alignment containing azobenzene molecules was produced. The PDLC was transparent because of this alignment. Upon photoirradiation to cause trans-cis photoisomerization of azobenzene molecules, the PDLC became translucent even at 30 °C. The…
We have developed amorphous carbon films in sequential layers and studied their intrinsic stress, composition, and stress relief mechanisms. The films were deposited by sputtering either thin, with fixed bias voltage Vb or thick, with alternative (positive-layer A/negative-layer B) Vb. In situ spectroscopic ellipsomet…
Freezing of charge-stabilized colloidal suspensions and relative stabilities of crystals and quasicrystals are studied using thermodynamic perturbation theory. Macroion interactions are modeled by effective pair potentials combining electrostatic repulsion with polymer depletion or van der Waals attraction. Comparing…
We report a study of dc transport properties up to 600 K and of the optical response over a broad spectral range of the two-dimensional (2D) dichalcogenide $2H\ensuremath{-}{\mathrm{TaSe}}_{2}$. Our findings suggest a dynamics of the charge excitation spectrum dominated by two relevant features: a Drude contribution,…
We report ab initio configuration interaction calculations on the optical transitions of the ${E}^{\ensuremath{'}}$ center, a hole trapped at an oxygen vacancy, $(---\mathrm{O}{)}_{3}{\mathrm{Si}}^{\ifmmode\bullet\else\textbullet\fi{}}$ ${}^{+}\mathrm{Si}(\mathrm{O}---{)}_{3}$, in silica. We found two competing excita…
We demonstrate by numerical simulations that spinodal decomposition of fluid mixtures is strongly dependent upon their ``fluidity,'' which characterizes the relative importance of the two relevant transport mechanisms, hydrodynamic flow and diffusion. Thus, it may not be ``universal,'' at least in two dimensions. For…
The current density is measured as a function of time for thin (⩽1000 Å) barium strontium titanate (BST) capacitors with platinum electrodes. The current density curve shows a peak prior to the onset of resistance degradation. The peak position on the time axis varies with applied voltage and temperature. The data are…
We report on a Raman spectroscopy study of float-zone crystalline silicon after exposure to a hydrogen plasma. New lines measured at 3601 and $2622\mathrm{cm}{}^{\ensuremath{-}1}$ are attributed to vibrational excitations of ${\mathrm{H}}_{2}$ and ${\mathrm{D}}_{2}$ molecules, respectively, positioned at the tetrahedr…
A new type of mesoscopic quantum effect in large-spin molecules possessing easy-axis anisotropy, such as Mn12, is predicted. The response of such a system to an external field applied perpendicular to the easy axis is considered. It is shown that the susceptibility of this system exhibits a peculiar peak of purely qua…