Materials Literature
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The effect of confinement on the exciton binding energies has been systematically investigated for two series of ZnO/ZnMgO multiquantum wells with various well widths and barrier heights. The exciton binding energies were extracted from the energy difference between the stimulated emission band induced by inelastic ex…
Enhancement of remanent polarization has been demonstrated in epitaxial “asymmetric” BaTiO3/SrTiO3 strained superlattices, in which the thickness ratio of BaTiO3 to SrTiO3 layers is changed at molecular layer order accuracy. The superlattices have been prepared on Nb-doped SrTiO3 (100) single-crystal substrates by a p…
To investigate cylindrical ultrathin copper nanowires, we performed atomistic simulations using the steepest descent method. The stable structures of the cylindrical ultrathin copper nanowires were multi-shell packs composed of coaxial cylindrical shells with {111}-like surfaces. Semiclassical orbits in a circle and c…
We have determined the crystal structure of the composite crystal [Ca 2 CoO 3 ] 0.62 CoO 2 , known as Ca 3 Co 4 O 9 , by a superspace group approach. Structural parameters were refined with a superspace group of C m (0 1- p 0) using powder X-ray and neutron diffraction data. The compound consists of two interpenetrati…
In Mn1−xZnxFe2O4 (x=0 to 1) nanosize particles prepared through hydrothermal precipitation we observe a decrease in particle size from 13 to 4 nm with increasing Zn concentration from 0 to 1. The lattice constant, a, for all Mn/Zn concentrations is found to be less than that for the corresponding bulk values. At speci…
Accurate estimates of the magnetic coupling in binuclear complexes can be obtained from ab initio configuration interaction (CI) calculations using the difference dedicated CI technique. The present paper shows that the same technique also provides a way to analyze the various physical contributions to the coupling an…
Thermoelectric materials have long been investigated for use in refrigeration. However, they currently occupy only niche markets because of their low efficiency. In his Perspective, Sales highlights recent advances toward more efficient thermoelectric materials that may find wider application in refrigeration and powe…
Abstract The changes produced by the effects of annealed and drawn fibers on the microstructure and macrostructure of nylon 66 fibers are considered. The optical properties and strain produced in nylon 66 fibers under different conditions are measured interferometrically at room temperature. Structural parameters are…
The recent advances in the toughening and reinforcing methods and theories in rigid inorganic particulate (RIP)-filled poly(propylene) (PP) composites have been reviewed. Studies have shown that under given conditions, in addition to the obvious increase of modulus, an obvious brittle–ductile transition also appears i…
We report on the magnetic, magnetoelastic, as well as the specific heat measurements of the electron-doped manganite ${\mathrm{Ca}}_{0.85}{\mathrm{Sm}}_{0.15}{\mathrm{MnO}}_{3}.$ The low-temperature monoclinic phase which is antiferromagnetic exhibits a first-order field-induced transition into the ferromagnetic state…
The synthesis of the first chiral superstructured corrole has been achieved by reacting an original bis(diaminophenyl)corrole with two chiral binaphthyl bis(acid chloride) handles.
We report x-ray scattering studies of nanoscale structural correlations in ${\mathrm{Nd}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{MnO}}_{3}$ and ${\mathrm{La}}_{1\ensuremath{-}x}(\mathrm{C}\mathrm{a},\mathrm{S}\mathrm{r}{)}_{x}{\mathrm{MnO}}_{3},$ $x=0.2--0.5.$ We find that the correlated regions possess a tempera…
A series of unprecedented hexanuclear silver(I) chalcogenolate complexes with bridging dppm ligands, [Ag6(μ-dppm)4(μ3-EAr)4](PF6)2 (EAr = SPh 1, SC6H4Me-p2, SePh 3, SeC6H4Cl-p4), have been synthesized and characterized. The X-ray crystal structures of 2 and 4 have been determined. The complexes were found to exhibit l…
tert-Butyl hydroperoxide (TBHP) efficiently converts a wide variety of sulfides to sulfoxides and sulfones. The method offers the advantage that one product or the other can be obtained in high purity by a modest variation of conditions. The reactions occur smoothly at 25minus sign50 C in chloroform and, to the extent…
Ionic exchange between electrostatically stabilized PMMA latex and aqueous dispersion of nanoparticles or rigid-rod polyelectrolytes of opposite sense is demonstrated to be a flexible approach to fabrication of polymeric-based nano and molecular composites, including layered silicates, indium tin oxide nanoparticles,…
Abstract 2‐Hydroxyethylmethacrylate (HEMA) was polymerized in an aqueous sulfuric acid– N,N ‐dimethylformamide (DMF) medium in a divided cell by an electrolytically generated mediator species titanium(III). Titanium(III)–hydroxylamine sulfate was used as the initiator redox system. The reaction was confined to the cat…
Abstract Influence of hydrogen‐bond‐breaking reagents such as urea on shrinkage temperature, isometric tension, swelling behavior, tensile strength, and percentage extension of native rat tail tendon (RTT) were examined. The swelling behavior was observed with polarizing optical microscopy and scanning electron micros…
We report the results of a spectroscopic ellipsometry (SE) and surface plasmon resonance (SPR) study of mercury vapor adsorption on polycrystalline and (111) gold films. We found that, when Hg adsorbs onto gold films, the change in the ellipsometric parameter delta (Δ) is proportional to the thickness of the adsorbed…
In order to know if the origin of ferromagnetism induced by the substitution of Co or Ni for Mn in ${\mathrm{LaMnO}}_{3}$ could be due to their divalent oxidation states, a set of ${\mathrm{LaMn}}_{1\ensuremath{-}x}{M}_{x}{\mathrm{O}}_{3}$ samples has been prepared for $x<~0.2$ and $M=\mathrm{Li},$ Zn, Ni, Co, Ga,…
Among the rush of papers published after the discovery of visible luminescence in porous silicon, a number of them claimed that an extraordinary behaviour had been found. However, after five years of struggling with increasingly sophisticated but not completely successful models, it was finally demonstrated that it wa…