Materials Literature
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We study the nematic-smetic A phase transition of binary mixture of parallel hard cylinders of different lengths. We use the Helmholtz free energy truncated at the second virial term. Changing values of q (length of a longer cylinder), x (composition) and η (packing fraction) of the cylinders, we obtained the transiti…
The structures of the title compounds, iron lutetium zinc oxides, can be described as a close packing of O atoms, with Lu atoms in octahedral voids and Fe and Zn atoms in tetrahedral voids. Blocks constituting m + 1 layers of Fe and/or Zn atoms along the c axis are alternately stacked with single layers of Lu along th…
Diamond (100) and (111) surfaces have been exposed to beams of atomic and molecular fluorine and chlorine in an ultrahigh-vacuum environment. X-ray photoelectron spectroscopy, low-energy electron diffraction, and thermal desorption techniques have been used to elucidate the chemistry involved. F atoms add to both the…
Nonhydrogenated diamondlike carbon films have been prepared by dual ion beam sputtering and ion-beam-assisted magnetron. The assistance parameters—ion energy, ion mass, ion flux/atom flux—have been systematically varied, and the films have been characterized by Rutherford backscattering spectroscopy, high-resolution t…
A model for a layered electron system is developed in which the electrons are treated completely quantum mechanically. In this model the ionic cores are replaced by parallel sheets of uniform positive charge. These charged sheets provide the neutralizing charge and the external potential which confines the interacting…
The title compound consists of the bulky 2,6-di-tert-butylphenoxy group and two phosphazene rings joined by a P-P bond [2.193 (2) angstrom]. The bulky group plays a predominant role in the distortion of the molecule as a whole. This distortion results in deviations of the benzene and phosphazene rings from planarity a…
We have succeeded in preparing RFe10.5V1.5 compounds and their corresponding nitrides RFe10.5V1.5Nx, where R=Y, Ce, Nd, Sm, Gd, Td, Dy, Ho, and Er. The structural and magnetic properties of RFe10.5V1.5Nx have been investigated by x-ray diffraction techniques and magnetic measurements and compared with those of RFe10.5…
A universal relationship between roughness and toughness of fractures is proposed and a new criterion to define brittle and ductile fracture is derived from the Griffith energy balance concept and fractal geometry.
From electrical resistivity and Hall coefficient measurements below 3 K on slightly reduced, semiconductive rutile single crystals with oxygen deficiencies ${\mathit{O}}_{\mathit{d}}$ between 3.7\ifmmode\times\else\texttimes\fi{}${10}^{18}$/${\mathrm{cm}}^{3}$ and 5.5\ifmmode\times\else\texttimes\fi{}${10}^{19}$/${\ma…
We report a systematic study of the resistivity and magnetic susceptibility of pure ${\mathrm{V}}_{2}$${\mathrm{O}}_{3}$, the original Mott-Hubbard system at half filling, for pressures 0\ensuremath{\le}P\ensuremath{\le}25 kbar and temperatures 0.35\ensuremath{\le}T\ensuremath{\le}300 K. We also study (${\mathrm{V}}_{…
Light-emitting porous silicon layers prepared on two types of boron-doped p and p+-Si substrates were studied by Raman spectroscopy in a broad frequency range (0–1100 cm−1). Standard phonon confinement model supported by new results from low-frequency scattering permit us to estimate consistently the characteristic di…
Angle-resolved photoemission spectra of the (100) and (110) faces of ${\mathrm{TiO}}_{2}$ have been recorded in the photon-energy range from 18 to 47 eV. These normal emission data have been analyzed on the basis of direct transitions into free-electron-like final states, yielding valence-band dispersion relations, E(…
Monte Carlo simulations of the fluctuating bond lattice model are used to determine the force between colloidal particles immersed in a nonadsorbing polymeric fluid. Monodisperse systems with chain lengths of 20 to 100 segments are studied at occupation fractions ranging from 0.1 to 0.6, covering the semidilute and de…
Temperature dependence of Debye-Waller factor in EXAFS, EELS and ARXPS is calculated for one-dimensional models on the basis of first principle quantum statistical method developed in the previous paper I. In contrast to diffraction Debye-Waller factors for crystal we have no need to worry about the divergence for the…
The crystal structure of recombinant chicken triosephosphate isomerase (TIM, E.C. 5.3.1.1) complexed with the intermediate analogue phosphoglycolohydroxamate (PGH) has been solved by the method of molecular replacement and refined to an R-factor of 18.5% at 1.8-A resolution. The structure is essentially identical to t…
We present band-structure and cluster-model calculations of ${\mathrm{LaCoO}}_{3}$ in the low-spin phase. The purpose of these calculations is to contrast and complement the results and conclusions of recent spectroscopic studies. The total density of states (DOS) is compared to the photoemission spectrum; the agreeme…
The crystal structure of the dimeric gene V protein of bacteriophage f1 was determined using multiwavelength anomalous diffraction on the selenomethionine-containing wild-type and isoleucine-47-->methionine mutant proteins with x-ray diffraction data phased to 2.5 A resolution. The structure of the wild-type protein h…
We present self-consistent ab initio total-energy calculations on ${\mathrm{TiO}}_{2}$ (110) surfaces for which the atomic geometry has been relaxed to equilibrium. For stoichiometric supercells we find no surface states in the bulk band gap, in accord with experiment. Oxygen vacancies on the surface give rise to Ti 3…
First-principles electronic-structure calculations were used to determine the electron-transport properties of ${\mathrm{RuO}}_{2}$ in the rutile structure. Our calculations were performed within the local-density approximation employing soft-core ab initio pseudopotentials and a plane-wave basis. The two independent…
Electronic structures of metallic ${\mathrm{LaNiO}}_{3}$ and insulating ${\mathrm{NdNiO}}_{3}$ are investigated using electron spectroscopies as well as band-structure and model-Hamiltonian calculations. It is shown that there is an increase in the transfer integral, ${\mathit{t}}_{\mathit{p}\mathit{d}}$ in ${\mathrm{…