Materials Literature
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We provide evidence of phase separation in La0.45Sr0.55MnO3−δ using electron spin resonance, magnetic force microscopy (MFM), x-ray diffraction, and magnetic and transport measurements. The results reveal that ferromagnetic and antiferromagnetic phase coexist at low temperature and that ferromagnetic and paramagnetic…
The relaxation kinetics of the photoinduced surface relief grating (SRG) formed on an azopolymer film after stopping laser beam writing has been systematically investigated. In addition to a photoinduced increase of the diffraction efficiency in the SRG, an anomalous further enhancement of the efficiency was observed…
Abstract An antioxidant derivative, 6‐sulfanylhexyl 3‐(3,5‐di‐ tert ‐butyl‐4‐hydroxyphenyl)propanoate, was synthesized and examined. With a radical initiator, the addition of this compound to pending vinyls of OH‐telechelic, low molecular weight liquid polybutadiene (LBH) was performed to various degrees of conversion…
We study the dynamics of polymers in a random disordered medium of fixed obstacles using kinetic Monte Carlo methods. The polymers can have monomers which have attractive (A-type), repulsive (R-type) or neutral (H-type) interactions with the fixed obstacles that comprise the disordered medium. Several classes of homop…
Specific behaviour of stress relaxation in GexSi1−x films grown on porous silicon based mesa substrates: computer calculations, P L Novikov, Yu B Bolkhovityanov, O P Pchelyakov, S I Romanov, L V Sokolov
Irradiation with infrared light is found to stimulate the electrical conductivity of a film of an organic polymeric conductor [poly(3,4-ethylenedioxythiopene) with polystyrene sulfonate]. The change in conductivity is found to be linear in the intensity of the irradiation (4–400 mW/cm2). Both frequency and time domain…
This letter shows that the effective permittivity ε for those metamaterials so far used to obtain a left-handed medium, consisting of 0.003 cm thick Cu strip wires, is dominated by the imaginary part of ε at 10.6–11.5 GHz frequencies. This is the region of a bandpass filter for microwaves, and therefore there is no pr…
Energy transfer at 1500 nm in lead fluoroborate glasses (PbO–PbF2–B2O3) codoped with Er3+ and Yb3+ is studied for the first time to the authors’ knowledge. A sample codoped with 1 mol. % of Yb2O3 and 0.01 mol. % of Er2O3 has a measured fluorescence lifetime of (1.30±0.07) ms and an energy transfer efficiency of 80%. A…
Emission spectra of GaTe single crystals in the range of 1.90–1.38 eV have been analyzed at different temperatures and excitation intensities by photoluminescence, photoluminescence excitation, and selective photoluminescence. A decrease in band gap energy with an increase in temperature was obtained from the redshift…
Abstract This study describes the effect of predrying sago starch, a tropical starch, on the resultant mechanical properties of starch/poly(ε‐caprolactone) composite materials. Sago starch was dried to less than a 1% moisture level in a vacuum oven and dispersed into a polycaprolactone matrix with an internal mixer at…
The formation and size of interstellar diamonds have been investigated by infrared spectroscopy in the laboratory. Employing hot-filament chemical vapor deposition (CVD) to synthesize the interstellar analogs, we successfully reproduced the infrared emission bands of nanodiamonds around HD 97048 and Elias 1. Analysis…
We have recently proposed [Phys. Rev. Lett. 87, 166101 (2001)] that any isotropic fluid should exhibit surface layering at its liquid–vapor interface above the triple temperature provided that the system has a low triple temperature. In this article we present an extensive study of systems with different isotropic pai…
Zone melting purification experiments have been carried out on the clathrate, Ba8Ga16Ge30. The impurities present have been identified and their approximate concentrations measured. Trace impurities were determined to be approximately 240 parts per million (ppm) in the most impure sample to 17 ppm in the most pure sam…
We report a detailed study of the morphology of TiO2:Co films grown on both LaAlO3 (001) and SrTiO3 (001) substrates by pulsed laser deposition. The films are optically transparent and ferromagnetic at room temperature with a magnetic moment of 1.7±0.4 μB/Co. Plan view transmission electron microscope studies show cle…
The effect of the substitution of B for C on the structure and magnetic properties of the Pr15Fe77C8−xBx (x=0–8) ribbons has been investigated. Microstructure analysis shows that the grain size and size distribution of the ribbons with x⩾2 do not change with B substitution. It is found that B substitution significantl…
The crystal and magnetic structures of the Rn+1Co3n+5B2n compounds (R=Pr, Nd, and Dy; n=1, 2, and 3) have been studied by high-resolution powder neutron diffraction and magnetization measurements. The RCo4B (n=1) and R3Co11B4 (n=2) samples are found to be single-phase compounds whereas R3Co11B4 is seen as impurity in…
Abstract Natural weathering of isotactic polypropylene (PP) plates (2 mm in thickness) was conducted for 15 months in the Philippines. Optical microscopy, scanning electron microscopy, and atomic force microscopy revealed that the surface layer (200–300 nm in thickness) was affected in the first month, and cracks are…
The kinetics of the polycondensation of 3,5-bis(trimethylsiloxy)benzoyl chloride ( BTMSBCl ) was investigated. 1D and 2D NMR techniques were applied to achieve a complete signal assignment of the structural units of the resulting polymer (poly(3,5-dihydroxybenzoic acid), PDHBA ), which was obtained after hydrolysis of…
The structures of fully and partially hydrogenated Si nanocrystals and nanoclusters are studied by geometric optimizations and molecular dynamics simulations based on an empirical tight-binding approach. It is shown that the structural properties of the hydrogen saturated Si nanocrystals have little size effect, contr…
We present an in situ study on the dispersibility of gold nanoparticles in different solvents by comparing the measured optical absorption spectra to the calculated absorption. Both uncapped and capped particles dispersed in a variety of solvents are investigated. In organic solvents such as chloroform and alcohols, d…