Materials Literature
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A new two-dimensional antimony sulfide has been synthesized under hydrothermal conditions in the presence of N, N ‘-bis(3-aminopropyl)ethylenediamine and characterized by single-crystal X-ray diffraction, thermogravimetry and elemental analysis. The product [C 8 N 4 H 26 ] 0.5 [Sb 7 S 11 ] ( M r = 1294.07) crystallize…
Phase transformations and magnetic properties of overquenched Pr7Fe88B5 ribbons during annealing have been investigated. X-ray diffraction and Mössbauer measurement indicate that melt spinning at different wheel velocities caused the as-quenched ribbons to have distinctive structures. Depending on their as-quenched st…
Effects of impurities with a strong and short-range potential are studied in carbon nanotubes within a k · p scheme. The calculated conductance approaches those obtained for nanotubes with a lattice vacancy when the strength of the potential is sufficiently large. The conductance at ε=0 is analytically shown to be qua…
In this article, we describe nanometer scale characterization of piezoelectric thin films of lead-zirconate-titanate. Using the electric field from a biased conducting atomic-force microscope tip, we show that it is possible to form and subsequently image ferroelectric domains. Using the cantilever in resonant mode, w…
Optically active 2,2′-bis(2-trifluoro-4-aminophenoxy)-1,1′-binaphthyl and its corresponding racemate were prepared by a nucleophilic substitution reaction of 1,1′-bi-2-naphthol with 2-chloro-5-nitrotrifluorotoluene and subsequently by the reduction of the resulting dinitro compounds. A series of optically active and o…
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…