Materials Literature
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We propose an optical configuration of a nontwist quarter-wave liquid-crystal cell for a high-contrast reflective display that can be applied to most nontwist display modes. By fabricating a homogeneous cell with the proposed configuration, we have demonstrated a high contrast ratio of 50:1 without using a wideband re…
First-principles calculations are employed to study ${\mathrm{SrTiO}}_{3}(001)$ $(1\ifmmode\times\else\texttimes\fi{}1)$ surfaces with both SrO and ${\mathrm{TiO}}_{2}$ termination. A detailed geometry of the relaxed systems, surface energy, and the individual relaxation energies of the two types of surface are obtain…
The bandwidth-controlled metal-insulator (MI) transition in pyrite-type NiS 2- x Se x has been investigated. The results indicate that the approach to the MI transition from the metallic side is profoundly affected by the presence of the antiferromagnetic metal (AFM) phase (0.4< x <1.0) immediately next to the MI phas…
A theoretical investigation of the dynamics of photopolymerization-induced phase separation (PIPS) and morphology development in a nematic liquid crystal (LC) polymer network mixture has been undertaken by incorporating photopolymerization kinetics into the coupled time-dependent Ginzburg-Landau (TDGL–Model C) equatio…
Lanthanum cobalt oxide LaCoO3 has a rhombohedrally distorted perovskite structure with the crystal space group of R3c.1-3) Raccah and Goodenough have reported that the crystal space group varies with increasing temperature from R3c to R3 around K. In the high temperature phase, two kinds of inequivalent Co atoms order…
Glasses with a composition xLi2O⋅(1−x)B2O3 were investigated by low-frequency Raman scattering in the composition range x=0–0.28. The evolution of the quasielastic line, the boson peak, the Debye frequency, and some other glass parameters with the composition was analyzed. The frequency of the boson peak ωb shifts wit…
The series of compounds ${\mathrm{Fe}}_{x}{\mathrm{Cr}}_{3\ensuremath{-}x}{\mathrm{Se}}_{4},$ with $0<~x<~3,$ has been prepared and various thermoelectric properties measured from 5 to 900 K. Unlike most thermoelectric materials that are band semiconductors with high carrier mobilities, ${\mathrm{Fe}}_{x}{\mathr…
An analytical approach to the quantification of electrostatic force microscopy and scanning surface potential microscopy images of systems with electric potential inhomogeneity has been developed in order to determine the interface potential in a donor-doped \ensuremath{\Sigma}5 ${\mathrm{SrTiO}}_{3}$ grain boundary.…
Reflectivity spectra of nine rare-earth sesquioxide ( R 2 O 3 ; R = La, Pr, Nd, Sm, Eu, Er, Tm, Yb and Lu) single crystals have been measured in the photon energy range from 0.5 to 50 eV at 300 K. The fundamental optical absorption has been clarified in connection with the electronic structure of R 2 O 3 . The absorpt…
We report first-principles electronic-structure calculations using local density approximation in density functional theory for hexagonally bonded hetero-sheets ${\mathrm{BNC}}_{x}$ consisting of graphite and boron-nitride strips. We find a class of electron states that are localized at borders of the heterosheet. Cal…
Graphite nanoparticles were prepared by the heat treatment of diamond nanoparticles in the range 900--1600 \ifmmode^\circ\else\textdegree\fi{}C. X-ray diffraction, transmission electron microscopy (TEM) and Raman scattering studies indicate that the onset temperature of the diamond-graphite transition is around 1200 \…
In this study we present the coarse-graining of one polymer chain in a melt to a single dimer. By using the projector operator formalism we derive the equation of motions for the dimer. The different forces that occur in this equation of motion are calculated from molecular dynamics simulations of the microscopic mode…
Ralstonia eutropha H16 degraded (mobilized) previously accumulated poly(3-hydroxybutyrate) (PHB) in the absence of an exogenous carbon source and used the degradation products for growth and survival. Isolated native PHB granules of mobilized R. eutropha cells released 3-hydroxybutyrate (3HB) at a threefold higher rat…
Using an atomic force microscope we have created nanotube junctions such as buckles and crossings within individual single-wall metallic carbon nanotubes connected to metallic electrodes. The electronic transport properties of these manipulated structures show that they form electronic tunnel junctions. The conductanc…
Within the last 20 years, advances in characterization methods, particularly in the field of high–resolution electron microscopy, have made it possible to probe the surface and internal structure of sub–100 nm particles, or nanoparticles. Such studies have indicated conclusively that surface–energy considerations in m…
We present an experimental determination of the vibrational density of states in nanocrystalline Fe and Ni by inelastic neutron scattering. Nanocrystalline specimens with different grain size and microstrain have been prepared by ball milling and thermal annealing. The vibrational density of states has been extracted…
We implemented a coarse-graining procedure to construct mesoscopic models of complex molecules. The final aim is to obtain better results on properties depending on slow modes of the molecules. Therefore the number of particles considered in molecular dynamics simulations is reduced while conserving as many properties…
We present angular-dependent magnetotransport and magnetization measurements on $\ensuremath{\alpha}\ensuremath{-}(\mathrm{ET}{)}_{2}\mathrm{MHg}(\mathrm{SCN}{)}_{4}$ compounds at high magnetic fields and low temperatures. We find that the low-temperature ground state undergoes two subsequent field-induced density-wav…
An intermediate orthorhombic ferroelectric phase has been found in oriented crystals of (0.92)Pb(Zn1/3Nb2/3)O3–0.08PbTiO3 (PZN-PT 92/8). Investigations have been performed by electrically induced polarization and strain methods, and reciprocal phase space mapping. The lattice parameters of this intermediate ferroelect…
Graphyne is a hypothetical carbon allotrope with a layered structure. We calculated the optimized geometries and electronic structures of three-dimensional graphyne in some possible stacking arrangements from symmetry considerations. The optimized lattice constants and the binding energy of graphyne are given in compa…