Materials Literature
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We have calculated the dielectric matrix for ${\mathrm{SrTiO}}_{3}$ and ${\mathrm{BaTiO}}_{3}$ perovskites and for Nb metal by the extended linear augmented plane wave--$\mathbf{kp}$ method. Dipole-allowed transitions from localized semicore states generate strong local fields, which shift the optical absorption band…
We present a detailed electron yield spectroscopy study of the pre-$K$-edge features of single-crystal diamond (100) and (111) surfaces which are induced by optical transitions from the C $1s$ core level into excited states. Both hydrogen-terminated and hydrogen-free surfaces were investigated. A sharp maximum at $\en…
Electrical contacts to porous silicon were formed by depositing various metals such as aluminum, gold, and titanium onto its surface. Low temperature current–voltage measurements were performed, which allowed us to identify the contact as a metal–insulator–semiconductor (MIS) structure. The parameters which characteri…
The dielectric secondary β relaxation process of poly(ethylene terephthalate) has been investigated by dielectric spectroscopy (DS) and thermally stimulated currents (TSC). To analyze the broad and asymmetric DS spectra, without previous assumptions on the shape and the number of overlapped loss components constitutin…
Microtubules of polyaniline (PANI) doped with HCl, HBF4, and β-naphthalene sulfonic acid (NSA) were synthesized by an improved in situ doping polymerization method. Ultraviolet-visible spectra, scanning electron microscopy, ESR, and X-ray diffraction characterized the molecular structure of the resulting PANI microtub…
Determination of the classical ground-state arrangement of N charges on the surface of a sphere (Thomson's problem) is a challenging numerical task. For special values of N we have obtained, using the ring-removal method of Toomre, low-energy states in Thomson's problem that have icosahedral symmetry. Lines of disloca…
Atomic and electronic structures of ${\mathrm{TaB}}_{2}(0001)$ and ${\mathrm{HfB}}_{2}(0001)$ surfaces are investigated with use of the first-principles pseudopotential calculations. Our calculated surface formation energies indicate that the graphitic-boron-terminated ${\mathrm{TaB}}_{2}(0001)$ surface is energetical…
A theory of linear and nonlinear optical susceptibilites of disordered composites consisting of nanospheres in a dielectric host (Maxwell Garnett composites) is developed. The theory is based on a spectral representation in the dipole approximation. Numerical computations are performed in the framework of the dipolar…
A series of A2B2 four-arm, miktoarm stars of polystyrene and polyisoprene have been synthesized. The morphological behavior of these materials has been characterized using TEM, SAXS, and SANS, and was found to agree in general with the predictions of Milner's theory for miktoarm star morphological behavior. One sample…
Archaeoglobus fulgidus, a hyperthermophilic, archaeal sulfate reducer, is one of the few organisms that can utilize D-lactate as a sole source for both carbon and electrons. The A. fulgidus open reading frame, AF0394, which is predicted to encode a D-(-)-lactate dehydrogenase (Dld), was cloned, and its product was exp…
In this work we report on direct measurements of the temperature and pressure dependences of the low-frequency dielectric constant along c axis $({\ensuremath{\varepsilon}}_{\ensuremath{\parallel}})$ of GaS, GaSe, and InSe. The temperature dependence of both the ordinary and extraordinary refractive indexes is also pr…
This manuscript presents an overview of work directed toward the creation of arbitrary micron-scale patterns of electroactive polymer films by the application of photolithography. A brief overview of work by other groups in the field is followed by a detailed description of work from our own labs which resulted in the…
Treatment of [U(Cp*) 2 Cl 2 ] and [U(COT)X 2 (THF) n ] (Cp* = η 5 -C 5 Me 5; COT = η 8 -C 8 H 8; X = BH 4 and n = 0, X = I and n = 2) with Na 2 dddt (dddt = 5,6-dihydro-1,4-dithiin-2,3-dithiolate) afforded the (dithiolene)uranium (IV) compounds [U(Cp*) 2 (dddt)] ( 1 ) and [Na(18-crown-6)] 2 [U(COT)(dddt) 2 ] ( 2 ); ox…
Films of Sm–Co have been sputtered on heated polycrystalline Al2O3 substrates. The effect of variations of the Sm content on microstructure and hard magnetic properties was studied for otherwise constant process parameters. As generally observed, the samples possess a magnetic texture where the easy magnetization dire…
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…