Materials Literature
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The linear response theory is applied to the interaction site model for the evaluation of static dielectric properties of a flexible water model. The atom–atom radial distribution functions derived from hybridization of the computer simulations and optimized cluster theory [A. D. Trokhymchuk, M. F. Holovko, E. Spohr,…
The Nd-Fe-B and Nd-Fe-Co-B magnet powders with the high coercivity (≥10 kOe) were obtained by the hydrogenation-decomposition-desorption-recombination (HDDR) process at temperatures between 800 °C and 900 °C. We studied magnetic properties and microstructures of the Nd-Fe-B systems during the HDDR process. The NdH2 ph…
We study the dynamic process of homogeneous quantum phase slippage in bulk charge-density-wave systems. A topological singularity, namely, a ``vortex shell'' in 3+1 dimensions is proposed as a trial wave function of the saddle-point field. The quantum tunneling rate is roughly \ensuremath{\Gamma}\ensuremath{\sim}exp(-…
The quasi-one-dimensional (1D) magnetoplasmons of a graphene tubule threaded by a magnetic field (B) have been evaluated exactly within the random-phase approximation. The plasmon frequency ${\mathit{w}}_{\mathit{p}}$ exhibits a very rich structure as a function of the magnetic flux through the tubule (\ensuremath{\va…
Hydrogen containing carbon (C:H) films have been prepared by ion beam deposition of 160 eV ethane ions on a carrier consisting of a Pt(111) single crystal surface covered with a monolayer of graphite. Several monolayers thick films deposited at 350 K contain hydrogen bound to sp, sp2, and sp3 hybridized carbon. Vibrat…
We have calculated the valence photoemission and bremsstrahlung isochromat spectra for TiO 2 , Ti 2 O 3 and VO 2 by means of an MO 6 cluster model (M=Ti, V). The result shows that the first ionization state and the lowest affinity state have considerable O 2 p character because of the large hopping matrix element betw…
The atomic structure of small-cross-section (\ensuremath{\approxeq}10 A\r{}), hydrogen-terminated silicon quantum wires is fully relaxed within the local-density approach showing bulklike coordination of the Si atoms. The electronic states near the fundamental gap (substantially blueshifted from that of bulk Si) show…
We use ab initio local-density-approximation methods to study the electronic and geometrical structure of the various C(100) surfaces. The calculated densities of states suggest that the surface states observed for the (2\ifmmode\times\else\texttimes\fi{}1) surface are attributable only to the clean C(100)(2\ifmmode\t…
Abstract Aggregates that may exist in poly(vinyl chloride) (PVC) solutions at ambient temperatures compromise the accuracy of SEC measurements of molecular weight distributions. Aggregate‐free solutions can be produced in 1,2,4‐trichlorobenzene (TCB) by controlling the dissolution time and temperature. SEC measurement…
Abstract The morphology of a number of polyamides (PA)—namely, PA‐66, PA‐6/PA‐66 blends, and PA‐6/PA‐66 copolymers—prepared from HCOOH solution and from the melt has been examined as well as the effect of annealing. In the blends, the PA‐6 crystallizes within the PA‐66 spherulites. When prepared from HCOOH solution at…
We report on measurements of the thermal conductivity of the quasi-one-dimensional conductor (${\mathrm{NbSe}}_{4}$${)}_{10}$${\mathrm{I}}_{3}$ between 80 and 320 K. We show that the thermal conductivity exhibits a well-defined minimum below the Peierls transition temperature ${\mathit{T}}_{\mathit{p}}$=285 K. Such be…
Dynamic pore collapse in porous materials is studied by analyzing the finite deformation of an elastic/viscoplastic spherical shell under impulsive pressure loading. Effects of dynamic loading rate, pore size, initial porosity, strain-rate sensitivity, strain hardening, thermal softening, and mass density of the matri…
Rhombohedral forms of layered boron nitride (r-BN) as mixtures with copper powders were shock compressed and quenched from pressures in the range 8–50 GPa. Recovered specimens were investigated by x-ray diffraction and electron microscopy. The graphite-like BN (h-BN) and turbostratic BN (t-BN) phases are observed in t…
Measurements are reported for the electrical conductivity of different compositions of silicate glasses containing copper and vanadium in the temperature range 200--500 K. The experimental results for the two systems are found to be very similar and are analyzed with respect to theoretical models existing in the liter…
Abstract The effect of the ethylene–methylacrylate copolymer as a chemical compatibilizer in the 50:50 blend of low‐density polyethylene (LDPE) and polydimethylsiloxane rubber (PDMS) has been studied in detail. Ethylene–methylacrylate (EMA) reacted with PDMS rubber during melt‐mixing at 180°C to form EMA‐grafted PDMS…
A convenient experimental method for determining the relative angular distribution of photoemission from solid materials has been proposed. Experiments were simultaneously simulated with the Monte Carlo model describing realistic photoelectron transport in solids. It has been proved that a major part of the observed d…
Abstract In polymer blends, the crystallization of the dispersed semicrystalline component depends on the type and distribution of the nucleating heterogeneities and on the level of the dispersion. Either fractionated or coincident crystallization may result. In this study, the effect of compatibilizers on the crystal…
A semiempirical molecular-dynamic density-functional approach is used to perform a systematic investigation of the stability, structure, and properties of quenched pure and hydrogenated amorphous carbon dependent on the mass density and the hydrogen concentration. By comparing the total structure energies for supercel…
We present a photoluminescence study of the free-exciton singlet and triplet ground states in GaTe as a function of temperature from 5 to 40 K. Over the range 5--25 K, the temperature variation of excitonic-emission line width and peak energy comes mainly from exciton--acoustic-phonon interactions via the deformation…
The photoluminescence and optical absorption properties of Zn-doped GaS crystals prepared by the iodine vapor transport method are reported. Undoped GaS crystals are also used for comparison. Zn substituted for a Ga site acts as an acceptor having a deep energy level and forms a complex with the iodine coactivator, wh…