Materials Literature
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We report the results of an investigation into the grain-size dependence of lattice structure for barium titanate (${\mathrm{BaTiO}}_{3}$) ceramics prepared by a sol-gel method. Raman and infrared spectroscopy, x-ray diffraction, and differential scanning calorimetry were used in combination with electron microscopy t…
A green emitting SrAl 2 O 4 : Eu 2 + , Dy 3 + phosphor with very bright and long lasting phosphorescence has been newly developed. The incorporation of Dy 3 + ion into the SrAl 2 O 4 : Eu 2 + system as an auxiliary activator dominates the phosphorescence, thermoluminescence, and photoconductivity characteristics of th…
The results of studies in recent years on the synthesis of polyimides with chains which are both flexible and rigid to the maximum extent are surveyed. The characteristic features of the formation of these polymers, their properties, and certain aspects of their practical applications are considered. It is shown that…
Poly(aryl ether phthalazine)s were found to undergo an exothermic reaction at a temperature range of 360–440°C. We elucidated the origin of the exothermic reaction and the physiochemical phenomena associated with it, based on thermal analyses, model compound studies, and 13C solid-state NMR studies. At elevated temper…
A mineral-filled in situ composite was prepared by a colloidal approach by first suspending kaolin filler particles in aqueous caprolactam, and then polymerizing caprolactam in situ at high pressure and temperature. The purpose of this colloidal in situ polymerization is to improve particle dispersion and to enhance i…
An ethylene-hexene copolymer was fractionated into five fractions and the density of short-chain branches was measured for each fraction. The slow crack growth behavior was measured on each fraction by sandwiching the small amount of fractionated resin of about 0.2 g between polyethylene grips. The resistance to slow…
Siloxane-incorporated epoxy (ESDG) copolymers were prepared by a hot-melt method. IR, 1H- and 13C-NMR are used to determine the structures. The data on the molecular properties indicate that reaction proceeded with a random polycondensation without involving the opening of the oxirane ring in the epoxy structure. Lowe…
Improved algorithms are proposed for a gradient plasticity theory in which the Laplacian of an invariant plastic strain measure enters the yield function. Particular attention is given to the type of finite elements that can be used within the format of gradient-dependent plasticity. Assuming a weak satisfaction of th…
The formation of chemisorbed O-phases on Ru(0001) by exposure to O_2 at low pressures is apparently limited to coverages Theta <= 0.5. Using low-energy electron diffraction and density functional theory we show that this restriction is caused by kinetic hindering and that a dense O overlayer (Theta = 1) can be formed…
Improved algorithms are proposed for a gradient plasticity theory in which the Laplacian of an invariant plastic strain measure enters the yield function. Particular attention is given to the type of finite elements that can be used within the format of gradient-dependent plasticity. Assuming a weak satisfaction of th…
We explore the effect of faceting on possible mechanisms for mass transport around electromigration voids in aluminum interconnects. Motivated by linear response estimates which suggest that particle flux would be much higher along steps than across terraces on a clean aluminum surface, we study step nucleation in the…
Kossel diagram images of liquid crystal blue phases reveal previously unobserved features, some previously predicted by Belyakov et al., associated with many-wave diffraction. The features consist of gaps in the Kossel lines and concentric interference fringes. A theory is presented predicting all the observed feature…
Optical absorption and fluorescence spectra have been systematically investigated in -doped crystals. The energy position and symmetry character of the Stark levels in the near-infrared region are deduced. The room-temperature absorption line strengths have been experimentally determined and the theory of Judd and Ofe…
By placing several Si δ-doped layers close to the surface of a GaAs molecular beam epitaxy–grown crystal, we achieve a compensation of the Schottky barrier and obtain a good Ohmic contact between an in situ deposited (without breaking the vacuum) Al metallization layer and a highly modulation doped (n++) conduction la…
A directional solidification study of succinonitrile doped with coumarin 152 was performed in which the pulling speed ${V}_{P}$ was gradually reduced in small steps. A spatial period-doubling instability was observed when ${V}_{P}$ reached $17.4\ensuremath{\mu}\mathrm{m}/\mathrm{s}$, in good quantitative agreement wit…
Epitaxial ferromagnet/semiconductor/ferromagnet sandwiches with the nominal structure δ Mn60Ga40/GaAs/δ Mn54Ga46 have been grown on GaAs(001) by molecular beam epitaxy, with spacer layer thicknesses ranging from 2 to 19 monolayers (ML) GaAs nominally. A strong antiferromagnetic coupling field μ0Hs=−12 to −39 mT at roo…
We have found a polaron ordered phase in low-doping rate ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{MnO}}_{3}$ ( $x\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.10$ and 0.15) by neutron scattering study. The onset temperature of the polaron order coincides with the point of resistivity upturn. T…
A response mechanism of nematic liquid crystals following the switching-on and off of an in-plane electric field when using the in-plane switching (IPS) mode was investigated. Simplified theoretical expressions, which were derived with an assumption that an in-plane electric field was applied to the liquid crystals, w…
Absolute differential ( - ) cross sections for low energy (1 - 10 eV) electron scattering from argon have been measured on two separate and different spectrometers using the relative flow technique. The data have also been analysed using phaseshift techniques. Comparisons are made between the present cross sections an…
Ab initio molecular orbital calculations were used to determine the structure and vibrational frequencies of the cyclic glycerol trimer, which represents the region of medium-range ordering in liquid and supercooled glycerol. The calculations reproduced the experimentally observed low-frequency Raman scattering peak (…