Materials Literature
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Magneto-optical Kerr effects have been investigated for perovskite-type hole-doped oxides ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{MnO}}_{3} (0<~x<~0.3)$ and ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{CoO}}_{3} (0<~x<~0.3)$ in the photon energy range between 0.9 and 5.3 eV…
We use tight-binding total-energy calculations to investigate the energetics and the cap formation mechanism of single-walled carbon nanotubes. The present calculations of the edge energy and strain energy suggest the growth of armchair nanotubes to be energetically more favorable than the growth of zigzag nanotubes.…
The yield stress behavior of a range of polyethylene materials which differ with respect to their short chain branch content has been studied. Measurements carried out over a wide range of temperatures have shown that there is a sudden transition in the behavior of the yield stress at a temperature which is dependent…
Au/SrTiO 3 (STO), Au/YBa2Cu3O7−x (YBCO)/STO, Au/STO/CeO2/STO, and Au/STO/MgO/STO multilayer structures on LaAlO3 substrates have been fabricated. Their properties are investigated at 1 MHz and at microwave frequencies (40 MHz–40 GHz) as a function of applied voltage, and in the temperature range between 20 and 300 K.…
A structural analysis of six alkaline sodium aluminate aqueous solutions by the X-ray diffraction method is reported. On average, each Al atom is surrounded by four oxygens, indicative of the predominance of Al(OH) 4 - (aq) in these solutions. Detailed least-squares fitting indicates that a significant contraction of…
The voltage-dependent dielectric constant (ε) of SrTiO3 (STO) thin films is the basis for developing cryogenic capacitors for tunable microwave applications. In this study, the effect of microwave signal level on nonlinear response at 1.7–1.9 GHz was examined by measuring the level of the third order intermodulation d…
We have studied the influence of the anodization temperature on the formation of porous Si for different current intensities. We have monitored the porosity, growth rate, luminescence, refractive index, and porous Si/bulk Si interface roughness. A strong decrease of the roughness was obtained for low temperature anodi…
Ferroelectric thin films (∼1.2 μm) of BaxSr1−xTiO3 with gradients in composition normal to the growth surface were formed on platinum substrates by metalorganic decomposition. Effective (pseudo) pyroelectric coefficients as large as 0.06 μC/cm2 K have been obtained from these active ferroelectric devices under the app…
A series of mononuclear transition metal complexes of the tetradentate (N 2 O 2 ) 6,6‘-bis(3‘‘-oxide-1‘‘-oxyl-4‘‘,4‘‘,5‘‘,5‘‘-tetramethylimidazoline-2‘‘-yl)-2,2‘-bipyridine (NIT-bpy) has been prepared and characterized by spectroscopic, magnetic, and single-crystal X-ray diffraction studies. The free NIT-bpy ligand is…
${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mathrm{MnO}}_{3\mathrm{\ensuremath{-}}\mathrm{\ensuremath{\delta}}}$ (LCMO) thin films are grown by pulsed laser deposition on a (100) ${\mathrm{SrTiO}}_{3}$ substrate at temperatures between 530 and 890 \ifmmode^\circ\else\textdegree\fi{}C. The magnetotransport prop…
Electrochemical measurements of hydrogen permeation through Pd/Nb multilayers on Pd substrates are described. Pronounced retardation of permeation is observed for small hydrogen contents. To clarify whether this effect is due to special interface hydrogen states, the permeation is modeled based on the bulk properties…
Electrically conducting polypyrrole-treated films have recently been shown to influence the morphology and function of mammalian cells in vitro. This type of polymer represents a possible alternative biomaterial for use in vascular implantation. The present study compared the in vitro biocompatibility of the five diff…
The real ( ε 1 ) and imaginary ( ε 2 ) parts of the dielectric function of polycrystalline samples of monoclinic CuO have been measured by spectroscopic ellipsometry in the 1.2–5.0-eV photon-energy range at room temperature. The CuO crystals having a grain size of the order of 1×1 mm 2 were successfully grown by a flo…
Poly(vinyl acetate- co -vinyl alcohol) copolymers (P(VAc- co -VA)) were synthesized by hydrolysis−alcoholysis of PVAc. The miscibility, crystallization, and morphology of poly(β-hydroxybutyrate) (PHB) and P(VAc- co -VA) blends were studied by differential scanning calorimetry, optical microscopy (OM), and SAXS. It is…
We present a comprehensive study of the aging process in HCl-doped polyaniline exposed to air. A complete set of measurements was carried out on three series of samples stemmed from the same preparation batch, and aged at 100, 120, and 140 \ifmmode^\circ\else\textdegree\fi{}C for times up to one month. All the samples…
We present Raman spectra of four semiconductor doped glasses and a single crystal of ${\mathrm{CdS}}_{0.55}{\mathrm{Se}}_{0.45}$ in the range 30--800 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ in the backscattering geometry. This includes the first-order Raman scattering from the disorder-activated zone-edge phonons a…
The use of starch microcrystals as biodegradable particulate filler is evaluated by processing composite materials with a weight fraction of starch ranging from 0 to 60%. In a previous work [Macromolecules, 29, 7624] the preparation technique of a colloidal suspension of hydrolyzed starch and the processing of composi…
Using the extended Hubbard model and sum-over-state method, we have calculated the linear polarizability $\ensuremath{\alpha}$ and the third-order nonlinear polarizability $\ensuremath{\gamma}$ for carbon nanotubes with finite lengths. We find that the chiral symmetry of nanotubes with finite length has a great effect…
We report an investigation of the properties of CdSe nanocrystal dispersions using small-angle x-ray scattering. These nanocrystals are prepared from organometallic precursors using high-temperature solution chemistry. The study provides direct and accurate measures of the nanocrystal size and size distribution. The l…
The electronic structures of the narrow ${t}_{2g}$ band systems ${\mathrm{YTiO}}_{3}$ and ${\mathrm{YVO}}_{3}$ are studied using the generalized gradient approximation (GGA) and local-density approximation (LDA)+U method. GGA fails in reproducing the insulating nature of ${\mathrm{YTiO}}_{3}$ and the correct magnetic…