Materials Literature
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Time-resolved optical measurements of electron-spin dynamics in a (110) GaAs quantum well are used to study the consequences of a strongly anisotropic electron g-tensor, and the origin of previously discovered all-optical nuclear magnetic resonance. All components of the g-tensor are measured, and a strong anisotropy…
We study the vicinal surface of the restricted solid-on-solid model coupled with the Langmuir adsorbates which we regard as two-dimensional lattice gas without lateral interaction. The effect of the vapor pressure of the adsorbates in the environmental phase is taken into consideration through the chemical potential.…
We report the high-pressure synthesis of novel superconductor MgB$_2$ and some related compounds. The superconducting transition temperature of our samples of MgB$_2$ is equal to 36.6 K. The MgB$_2$ lattice parameters determined via X-ray diffraction are in excellent agreement with results of our ab initio calculation…
Silica thin films with a two-dimensional (2D) hexagonal structure were produced from TEOS and the F127 triblock copolymer PEO 106 PPO 70 PEO 106 . The structure of the films was deduced from transmission electron microscopy (TEM) performed on microtomed sections and from a 2D X-ray scattering technique adapted for fil…
Polystyrene−clay nanocomposites have been prepared using a bulk polymerization technique. Three new “onium” salts have been used to prepare the nanocomposites, two are functionalized ammonium salts while the third is a phosphonium salt. By TGA/FTIR, both ammonium and phosphonium treatments have been shown to degrade b…
It is demonstrated that the commercially-available imaging plate (IP) using BaFBr:Eu photostimulable phosphor is useful as a phosphore material for 2D UV image sensor though the sensitivity of the IP for UV-ray is not so high. The new phosphore materials as alternative materials for the IP are surveyed for many possib…
The U.S. Army Corps of Engineers is tasked with designing and building navigation and flood control structures located within bodies of water including rivers, waterways, and coastal areas. Each of these structures has a foundation system traditionally designed for construction "in-the-dry", i.e. within a pre-installe…
New alkaline free phosphate glass compositions are presented. Phosphate glass with a temperature coefficient of refractive index close to zero and a good chemical durability can be achieve. These new glass compositions are very promising for high quality optical fibers with a constant mode profile, and erbium doped fi…
New perovskite-type lithium ion conductors [Ag y Li 1 - y ] 3 x La 2/3 - x TiO 3 were synthesized and their crystal structure and ionic conductivity were characterized. The La 3+ and vacancies contents have been fixed ( x = 0.09) and the substitution of Ag + for Li + was varied from 0 to 1. The X-ray powder diffractio…
This paper reports the preparation of planar waveguides in an Er<SUP>3+</SUP> doped tellurite glass with a composition, 15Ns<SUB>2</SUB>O-25WO<SUB>3</SUB>-60TeO<SUB>2</SUB>- 1Er<SUB>2</SUB>O<SUB>3</SUB>, by Ag<SUP>+</SUP>-Na<SUP>+</SUP> ion-exchange. The glass was chemically stable during ion-exchange process. Single-…
Structural characteristics of amorphous silicon (a-Si) have been examined by molecular-dynamics calculations using the Tersoff interatomic potential. It was confirmed that the computer-generated atomic configurations reproduce well the structural and dynamical properties of a-Si obtained experimentally. The a-Si netwo…
In this work we report on spectroscopic properties of Er<SUP>3+</SUP>-doped aluminum fluorophosphate glasses of molar composition 29.8AlF<SUB>3</SUB>:3.5 MgF<SUB>2</SUB>: 19.8 CaF<SUB>2</SUB>: 10.9 SrF<SUB>2</SUB>: 12.8 BaF<SUB>2</SUB>: 8.4 YF<SUB>3</SUB>:9.8 ZrF<SUB>4</SUB>:4 NaPO<SUB>3</SUB>:1 ErF<SUB>3</SUB> and 30…
A novel strategy for the synthesis of well-defined oligo(phenylenevinylene)s was developed. The procedure is entirely based upon two coupling processes, both involving vinyltrimethylsilanes. Bis(styryl)benzenes 2a-g bearing two octyloxy groups in the central aromatic ring and various substituents on the external aroma…
Nanotubes have become attractive subjects in solid-state physics owing to their potential applications in nanotechnology. Their symmetry is one of the important tools in theoretical investigations. Here a review is presented of the symmetry groups of the single-wall nano- and microtubes considered in literature: BN, G…
Characteristics of porous structure of silica gel Si-60 (pristine and covered by different amounts of pyrocarbon prepared by pyrolysis of acenaphthene, acetylacetone, and glucose, then heated at 500 °C in air or hydrothermally treated (HTT) at 150 or 200 °C, and also heated at 500 °C) were analyzed by using TEM, 1 H N…
We present here a detailed Rietveld analysis of the structure of paraelectric and antiferroelectric phases of Sr 0.70 Ca 0.30 TiO 3 using powder XRD data. It is shown that the observed antiferroelectric superlattice reflections can be explained by doubling of the C o parameter of the orthorhombic paraelectric phase. T…
Results of a detailed dielectric study of phase transition in Sr 1- x Ca x TiO 3 in the composition range 0.18⩽ x ⩽0.40 are reported. It is shown that the temperatures T ' m and T '' m corresponding to the peaks in the real (ε'( T )) and imaginary (ε''( T )) parts of the dielectric constant, respectively, are not only…
This electron-density study on corundum (alpha-Al2O3) is part of the Multipole Refinement Project supported by the IUCr Commission on Charge, Spin and Momentum Densities. For this purpose, eight different data sets (two experimental and six theoretical) were chosen from which the electron density was derived by multip…
An empirical fitting procedure is applied to derive interatomic potential parameters for a model phase transition system, namely potassium tetrachlorozincate (K(2)ZnCl(4)). The derived potential is found to reliably model the known crystallographic structure for the ferroelectric and paraelectric phases of this compou…
Abstract An experimental procedure is presented to describe the PVT behavior of multiphase polymeric materials in a wide range of cooling rates. In particular, the procedure is applied to a typical multiphase industrial polymer, that is, an industrial polypropylene–ethylene‐propylene rubber (iPP–EPR) copolymer with a…