Materials Literature
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Usual Penrose tilings are defined by a set of five phases gamma j which add up to an integer. The authors study the general case where the phases add up to any number and show that these generalised tilings can be obtained with four tiles (two thick rhombi and two thin rhombi) with different colourings of the edges. T…
Thermoreflectance spectra of Pb1-xGexTe (x=0, 0.02, 0.03, 0.07 and 0.1) have been investigated in the energy range 1.2 to 4.4 eV at temperatures above and below the phase transition temperature. The change of the interband transitions on the Ge content x in the cubic phase (300 K) have been obtained. Thermoreflectance…
A lattice dynamics model for ionic crystals with complex anions is developed and applied to experimental phonon dispersion curves for orthorhombic CaSO 4 . The model treats the sulphate as a rigid unit and includes long-range Coulomb interactions. Fifteen force constants and three atomic charges are fitted to the expe…
Wheat straw-g-polyacrylonitrile (PAN), containing 40% PAN, was saponified with sodium hydroxide and isolated under three sets of saponification and work-up conditions. Each reaction mixture was separated into a water-soluble and a water-insoluble fraction, which were individually analyzed for percentages (by weight) o…
Using the Guinier plot, the 200 reflection profile of ramie cellulose I was resolved into two components. One component represented a crystallite size of ∼ 20 Å, and the other component represented a crystallite size of ∼ 61 Å. These components were followed during the conversion of cellulose I to Na–cellulose I, in o…
When cellulose is mercerized slowly, the initial conversion is from the cellulose I crystal structure to that of Na–cellulose I. The conversion is a crystal-to-crystal phase transformation, without passage through an amorphous state. The analysis of crystallite sizes of cellulose I and Na-cellulose I during this trans…
Molecular-dynamics calculations are used to characterize the structure and dynamics of the two solid bilayer phases of the n-alkane tricosane (${\mathrm{C}}_{23}$${\mathrm{H}}_{48}$). In the crystalline orthorhombic phase at 38\ifmmode^\circ\else\textdegree\fi{}C, chains undergo translational, rotational, and torsiona…
We obtain quasicrystalline structures in Monte Carlo simulations of a simple two-component Lennard-Jones system in two dimensions. The quasicrystal, which shows tenfold symmetry, appears to be an equilibrium state of the system. Although the structure corresponds to tiling of the plane with rhombuses, it is not a Penr…
Using electroreflectance spectroscopy, we have observed new optical transitions near 0.76, 1.25, and 2.31 eV in an ordered strained-layer Ge-Si superlattice. The possible origins of these transitions are discussed in terms of modification of the electronic band structure by the sample structure.
Structural transformation of transition-metal monopnictides and monochalcogenides from the NiAs type to the MnP type is studied microscopically by calculating matrix elements of the electron-lattice interaction on the basis of the electronic bands obtained by the self-consistent augmented-plane-wave (APW) method. From…
A new basis is presented for the calculation of reflection coefficients of x rays by multilayer artifacts. Thin film interference is treated at an atomic plane level using an iterative 2 x 2 matrix method. Analytic and computational comparisons are made with the conventional dielectric approach for TM and TE polarizat…
Get PDF Email Share Share with Facebook Tweet This Post on reddit Share with LinkedIn Add to CiteULike Add to Mendeley Add to BibSonomy Get Citation Copy Citation Text Patrick Jelinsky and Sharon Jelinsky, "Low reflectance EUV materials: a comparative study," Appl. Opt. 26, 613-615 (1987) Export Citation BibTex Endnot…
Magnetic measurements were made on the cubic perovskite-type SrFe 1- x Co x O 3 (0≤ x ≤0.2). It was observed that with decreasing x the paramagnetic Curie temperature θ p and the Curie temperature T C decrease and the Néel temperature T N of the screw phase increases. It is argued from these results that the main magn…
The exponential-band-tail (Urbach-tail) problem for structurally disordered material is treated by a simple model in which quantum wells (used to model the effects of local disorder) trap states in the gap. The density of states in the gap is calculated and is shown to have approximately exponential behavior over a ra…
Experiments on the anomalies in surface-plasmon dispersion on periodically modulated single- and multilayered structures are analyzed. These anomalies arise if the dispersion curves intersect in the reduced Brillouin zone. Experiments on different types of gratings and for different excitation methods, e.g., excitatio…
An improved smoothing procedure is used to extract more information from x-ray-absorption spectra by second-derivative analysis. The true energy position of the maxima and full width at half maximum are measured for all features. The excitonic peak is present for all compositions and is well correlated with the 3d-ele…
We present high-resolution synchrotron-radiation core-level photoemission results which show that the room-temperature deposition of Co onto GaAs(110) induces limited substrate disruption, leading to Ga and As intermixing with the metal overlayer. High-energy Auger electron diffraction and low-energy electron diffract…
Magic-angle spinning nuclear magnetic resonance measurements have been performed on $^{29}\mathrm{Si}$ nuclei in amorphous silica before and after densification \ensuremath{\sim}16% by pressure compaction at 50 kbar and 600?deC. The pressure-induced shift in the Si---O---Si bond-angle distribution maximum from 143\ifm…
Segregation and transport coefficients of impurities at the Si/SiO2 interface have been studied. A brief model has been proposed which relates the two coefficients to the oxidation rate and the impurity concentrations at both sides of a Si/SiO2 interface. The model enables us to obtain the transport coefficients from…
The molecular dynamics method is used to study the liquid–vapor interface of the Stockmayer fluid. We compare our results for the singlet density-orientation distribution function and surface tension with the predictions of integral equation and perturbation theory. We find that at low temperature and high moment cond…