Materials Literature
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In an earlier paper, W. Kohn had qualitatively introduced the concept of "nearsightedness" of electrons in many-atom systems. It can be viewed as underlying such important ideas as Pauling's "chemical bond," "transferability" and Yang's computational principle of "divide and conquer." It describes the fact that, for f…
A stacked plate model for the vibration of multi-layered graphene sheets (MLGSs), in which the van der Waals (vdW) interaction between layers is described by an explicit formula, is presented. Explicit formulae are derived for predicting the natural frequencies of double- and triple-layered graphene sheets, and they c…
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The effect of grain boundary structure, either rough or faceted, on diffusion‐induced grain boundary migration (DIGM) has been investigated in BaTiO 3 . SrTiO 3 particles were scattered on the polished surfaces of two kinds of BaTiO 3 samples with faceted and rough boundaries and annealed in air for the samples with f…
Abstract Hot filament chemically vapor deposited (HFCVD) boron doped diamond films were grown on monocrystalline silicon (111) doped with B/C ratios of 4000, 8000 and 12,000 ppm. Scanning electron micrographs show that the films are composed of well‐faceted microcrystallites ranging in size from about 1 to 5 µm with n…
The leaching behavior of Na from soda–lime–silicate glass was investigated by preparing glass powders with average particle diameters of 53 and 19 μm, and leaching in HNO 3 at 90°−140°C. A new theoretical equation for Na leaching from a spherical particle is proposed based on the assumption that a rate‐determining pro…
Abstract N -Methylene(morpholinium) ions (carbenium-iminium ions) are responsible for uncontrollable reactions of Lyocell dopes – solutions of cellulose in N -methylmorpholine- N -oxide monohydrate at process temperatures of approximately 100°C – as they are able to induce autocatalytic decomposition of the solvent. T…
Abstract Ribbon and rod sapphire pulling has been performed in three different crystal growth equipments in order to study the effect of the installation, of the atmosphere, of the die shape, of the feed material and of the pulling rate on the distribution, number and diameter of the characteristic voids (micro‐bubble…
The performance and expected lifetime of piezoelectric ceramic components are ultimately defined by bulk material fatigue processes. In this work, strain accumulation of a ferroelectric/ferroelastic ceramic lead zirconate titanate is characterized under mechanical cycling using four‐point bend bar geometry. Strain acc…
Abstract Detailed characteristics of excitonic emission in diamond have been studied by theoretical considerations taking into account the indirect semiconductor properties to calculate precise simulated spectra of the excitonic emission. The simulated excitonic emission spectra agree well with the observed spectra in…
In this work continuum and lattice Monte Carlo simulation methods are used to study the adsorption of linear and comb polymers on flat surfaces. Selected polymer segments, located at the tips of the side chains in comb polymers or equally spaced along the linear polymers, are attracted to each other and to the surface…
Optical heterodyne-detected optical Kerr effect (OHD-OKE) experiments are presented for the supercooled liquid acetylsalicylic acid (aspirin - ASP). The ASP data and previously published OHD-OKE data on supercooled dibutylphthalate (DBP) display highly damped oscillations with a periods of approximately 2 ps as the te…
We investigate the electromagnetic response of a periodic checker- board consisting of alternating rectangular cells of positive refractive index (ε = +1, μ = +1) and negative refractive index (ε = −1, μ = −1). We show that the system has peculiar imaging properties in that it reproduces images of a source in one cell…
Abstract Nitrous acid deaminative depolymerisation was used to prepare three chitosan oligomer (CO) mixtures from high-molecular weight chitosan. These mixtures of chitosan oligosaccharides were analysed by electrospray ionisation mass spectroscopy, potentiometric titration and gel permeation chromatography. A method…
We report the colossal negative electroresistance (ER) in the p-n heterostructure of La0.67Ca0.33MnO3−δ (LCMO) and Nb-doped SrTiO3. For a vacuum-annealed sample, a maximum ER of 4×104% can be reached by 1 mA current and magnetic field has remarkable influence on the ER of the sample. It is interesting that the magneto…
The performance of coaxially gated, zero-Schottky-barrier, carbon nanotube field-effect transistors is investigated for gate lengths down to 2 nm with source and drain underlaps. Such devices can have nearly ideal subthreshold slopes of ∼63mV∕dec and maximum on∕off current ratios of 2.2×106 assuming 0.0–0.4 volt swing…
Abstract Measurements are reported of the mechanosorptive strain in Pinus radiata specimens stressed either in torsion or in bending. It is demonstrated that, to secure valid data, correction must be made for the moisture-induced distortion at zero load. A series of measurements can be made on a single specimen if two…
Conductivity profiles of nitrogen‐graded zirconia from nitridation of 2 mol% yttria‐doped tetragonal zirconia polycrystals (2Y‐TZP) were determined using microcontact impedance spectroscopy. Local conductivity variations were interpreted in terms of nitrogen concentration and the morphological distribution of the tetr…
Abstract Optical anisotropy of the layer semiconductor GaSe has been studied by photoluminescence (PL) and Fourier Transform Infrared Spectroscopy (FTIR). The PL spectra are dominated by two closely positioned emission bands resulting from the free exciton and the bound exciton connected direct band edge of GaSe. Phot…
BaTi 1−2 y Ga y Nb y O 3 (BTGN) (0≤ y ≤0.35) powders were synthesized at 1300°C by the conventional solid‐state method. Room temperature x‐ray diffraction patterns for y ≤0.025 and 0.05≤ y ≤0.30 can be indexed as the tetragonal ( P 4 mm ) and cubic ( Pm m ) polymorphs of BaTiO 3 , respectively, whereas y =0.35 consist…