Materials Literature
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Optical absorption and emission intensities are investigated for ${\mathrm{Nd}}^{3+}$ ions in a $\ensuremath{\alpha}\ensuremath{-}{\mathrm{Nd}}^{3+}{:\mathrm{L}\mathrm{a}\mathrm{S}\mathrm{c}}_{3}{(\mathrm{B}\mathrm{O}}_{3}{)}_{4}$ crystal. Oscillator strengths of transition were measured from absorption spectra record…
Multiphoton photoemission spectroscopy of graphite using 267 nm (4.65 eV) and 400 nm (3.1 eV) excitation wavelength reveals spectroscopic features that allow the identification of the multiphoton excitation process and that correspond to the known bulk band structure. In addition, the $n=1$ and $n=2$ image potential s…
The figure of merit for multilayer thermionic refrigeration is discussed in terms of an effective B factor, which has a similar definition as the B factor in thermoelectrics. We show that high efficiencies for cooling or power generation are only obtained with very high values of this B factor. Such high values can on…
Applying a dc electric field across a fused silica sample at elevated temperatures followed by cooling the sample with the field applied (thermal poling) leads to a second-order nonlinearity that has been linked to the formation of a space-charge region in bulk glass. The first microscopic information on the extent of…
Ito, Moynihan, and Angell [Nature 398, 492 (1999)] compared the kinetic and thermodynamic measures of a glassformer’s “fragility.” For the liquids they considered which include molecular, covalent, and ionic substances, thermodynamic fragility and kinetic fragility follow the same order, suggesting that the thermodyna…
Characterization and magnetic properties of Fe–Co(C) nanocapsules were investigated systematically by means of x-ray diffraction, Mössbauer spectroscopy, x-ray photoelectron spectroscopy, transmission electron microscopy, energy dispersive spectroscopy analysis, chemical analysis, oxygen determination, and magnetizati…
We present a first-principles study of the adsorption of a palladium monolayer on the polar MgO (111) surface. On the clean unreconstructed MgO (111) surface, our spin-polarized calculations confirm the existence of partially occupied states in the gap on both oxygen and magnesium terminations. The adsorption characte…
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The thermodynamic behavior of the carbon schwarzite fcc $({\mathrm{C}}_{36}{)}_{2}$ has been studied by tight-binding molecular-dynamics simulations at constant temperature and pressure. The system is totally ${\mathrm{sp}}^{2}$ bonded and it can be represented as a folded graphite sheet made by hexagonal and heptagon…
The heat shock response in alpha proteobacteria is unique in that a combination of two regulators is involved: a positive regulator, RpoH (sigma(32) homolog), found in the alpha, beta, and gamma proteobacteria, and a negative regulator, HrcA, widely distributed in eubacteria but not in the gamma proteobacteria. To ass…
Plasma-enhanced chemical vapor deposition of vanadium pentoxide thin films from a vanadyl(IV) β-diketonate compound has been performed in a low-pressure reactor under different operating conditions. The effect of various parameters, such as the flow rates of the carrier and reactive gas and the substrate temperatures,…
We discuss the electronic properties of ${\mathrm{VO}}_{2}$ in its monoclinic, insulating phase, by comparing the results of quasiparticle band structure calculations obtained within a model $\mathrm{GW}$ scheme with those of both LDA calculations and available experiments. Our calculations are based on the full-poten…
Early stages of crystallization of polymers may be viewed as thermoreversible physical gelation in which molecular connectivity is introduced by crystallization. Effects of shear strain on the early stages of crystallization of a commercial isotactic polypropylene are studied by dynamic mechanical experiments. Shear c…
Absorption and low-frequency Raman-scattering experiments have been performed on thin films consisting of small silver clusters embedded in a porous alumina matrix. When the Raman excitation wavelength is close to the maximum (\ensuremath{\approx}420 nm) of the Mie band (dipolar surface plasmon resonance) the Raman sp…
The structure and electronic structure of amorphous ${\mathrm{WO}}_{3}$ were studied with first-principles density-functional calculations. Upon amorphization, a large increase of the band gap is observed. The empty states exhibit a tendency towards localization. We studied the filling of these states as induced by ad…
We present the results of a first principles investigation of the equilibrium properties of c-plane $\ensuremath{\alpha}\ensuremath{-}{\mathrm{Al}}_{2}{\mathrm{O}}_{3}$ surfaces. The stable structure for the $1\ifmmode\times\else\texttimes\fi{}1$ clean surface is Al terminated with a stoichiometric composition, while…
A scaling theory of local-field fluctuations and optical nonlinearities is developed for random metal-dielectric composites near a percolation threshold. The theory predicts that in the optical and infrared spectral ranges the local fields are very inhomogeneous and consist of sharp peaks representing localized surfac…
We report here a theoretical model describing specific mechanisms of heat transport in as-prepared and oxidized meso-porous silicon layers. The model is in good agreement with experimental measurements performed by micro-Raman scattering on the layers surface. For the first time, thermal conductivity inhomogeneity alo…
In order to understand the role of hole doping on electronic structure, phase stability and magnetic properties of ${\mathrm{LaCoO}}_{3}$ generalized-gradient-corrected, relativistic first-principles full-potential density functional calculations have been performed for ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{…
The electronic structures of the perovskite oxides $\mathrm{La}M{\mathrm{O}}_{3}(M=\mathrm{C}\mathrm{r},\mathrm{}\mathrm{M}\mathrm{n},\mathrm{}\mathrm{F}\mathrm{e},\mathrm{}\mathrm{C}\mathrm{o},\mathrm{}\mathrm{and}\mathrm{}\mathrm{Ni})$ have been studied in the local-spin density approximation $\mathrm{LSDA}+U$ metho…