Materials Literature
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Raman spectra of the high-frequency (\ensuremath{\sim}1600 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$) graphite interlayer modes have been studied in several Li-graphite intercalation compounds (GIC's) ${\mathrm{LiC}}_{\mathrm{p}}$=6,12,17,18. In stage-2 ${\mathrm{LiC}}_{17}$ we have also used these modes to study the…
We consider an infinite chain of atoms, where the bond lengths between neighbouring sites take two values, according to a quasi-periodic rule, associated to a circle map with an irrational rotation angle. In a particular case, this construction is related to the projection method used to describe quasi-crystals. The s…
Defect centers induced in GeO2 glass by either 100-KeV x rays at 77 K or γ rays at room temperature were studied by electron-spin resonance. The model of a singly charged oxygen vacancy defect center for the Ge E′ center (g∥ =2.0012, g⊥ =1.9945) was confirmed by the observation and computer simulation of the 73Ge hype…
We report on resonant and nonresonant Raman scattering by acoustic phonons in Fibonacci GaAs-AIAs superlattices. Spectra off resonance are dominated by doublets centered at frequencies that follow a power-law behavior, in good agreement with numerical calculations based on a continuum model. Resonant data show a weigh…
Replacement of B (B=S or Se) by Bi in Ge${B}_{4}$ produces semiconductive glasses with n-type thermoelectric power, in contrast to almost all other chalcogenide glasses, which are p type. I describe theoretically a structural model which explains why carrier-type reversal occurs for Bi replacement, but not for Sb repl…
We have studied the formation of amorphous silicon by rapid quenching of the melt using the Stillinger-Weber potential to model the interaction between silicon atoms. By quenching the melt at a rate of 3\ifmmode\times\else\texttimes\fi{}${10}^{14}$ K/s we form amorphous silicon. Excellent agreement with the experiment…
Optical band gaps, ${E}_{g}$, up to 0.5 eV higher than in single-crystal samples, are observed for chemically deposited films of CdSe and explained in terms of a quantum-size effect, whereby the electrons are localized in individual crystallites. The increase in ${E}_{g}$ depends strongly on deposition temperature, wi…
The relative viscosities at 25°C of solutions containing 12% wt/vol poly(vinylbutyral) in pure methanol (MeOH), 1:1 methyl iso-butyl ketone (MIBK)/MeOH by volume and 9:1 MIBK/MeOH were in the ratio 1.0:0.9:4.3, respectively. The apparent activation energy for flow was 20 kcal/mol in the latter solution and only 8 kcal…
An analysis has been made of Angstrom's method for the measurement of the thermal diffusivity of solids when the length of the sample is short and when the end remote from the periodic heat source is thermally isolated. The results of the analysis have been applied to experimental data obtained from a short specimen o…
Absolute differential cross sections sigma ( theta ) for elastic electron scattering from mercury atoms were measured in the energy range from 25 to 300 eV at scattering angles up to 135'. The smallest scattering angles were 2 and 7' at 300 and 25 eV, respectively. A target cell was used in which the pressure could be…
Hydrogenated amorphous boron films have been produced by a toroidal glow discharge of B2H6/He mixtures at low pressures (10−2 Torr). Chemically stable pure films with a low hydrogen content can be formed at a moderate substrate temperature (∼200 °C) when the diborane flow rate is raised above 10 sccm with the discharg…
The theory of forming a coherent twinning array in a parent phase is studied for a tetragonal to orthorhombic displacive transition. We find that this structure can be stabilized without the use of dislocations by a long-range interaction between the twin boundaries which is mediated via the parent phase. The dynamics…
Thin films of Y-Ba-Cu-O superconductors on (100) SrTiO3 were prepared using the pulsed excimer laser evaporation technique. After an annealing treatment in oxygen the films exhibited superconductivity with zero resistance at 85 K with transition widths (90%–10%) as narrow as a 2 K. A considerable amount of orientation…
A general review of conventional magnetic shielding is presented. Several possible definitions of the term 'shielding factor' are given, taking into account the ferromagnetic nature of shielding materials. An alternative treatment of single-layer axial shielding for a cylindrical shield is presented and compared to a…
In order to characterise the interplay between quasiperiodicity and order in one dimension, the authors consider sequences of 0 and 1 generated by a circle map. These sequences, which generalise the Fibonacci sequence, describe the quasiperiodic ordering of atoms and vacancies on a line. They study in a quantitative w…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCompressibility and high-pressure phase transition of a metalloporphyrin: (5,10,15,20-tetraphenyl-12H,23H-porphinato)cobalt(II)Robert M. Hazen, Thomas C. Hoering, and Anne M. HofmeisterCite this: J. Phys. Chem. 1987, 91, 19, 5042–5045Publication Date (Print):September 10, 19…
The electronic band structures of cubic and tetragonal iron monosulphide have been obtained for self-consistent linear muffin-tin orbital calculations within the atomic sphere and local density approximations. The Fe-S bond is seen to be mainly ionic with little covalent mixing. In calculations excluding spin polarisa…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynergy in N-ethylformamide dehydration by mixtures of molybdenum trioxide and antimony oxide (.alpha.-Sb2O4)B. Zhou, S. Ceckiewicz, and B. DelmonCite this: J. Phys. Chem. 1987, 91, 19, 5061–5067Publication Date (Print):September 10, 1987Publication History Published online1…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectron pairing in dilute liquid metal-metal halide solutionsA. Selloni, R. Car, M. Parrinello, and P. CarnevaliCite this: J. Phys. Chem. 1987, 91, 19, 4947–4949Publication Date (Print):September 10, 1987Publication History Published online1 May 2002Published inissue 10 Sep…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTChemical effects on the optical properties of semiconductor particlesY. Wang and N. HerronCite this: J. Phys. Chem. 1987, 91, 19, 5005–5008Publication Date (Print):September 10, 1987Publication History Published online1 May 2002Published inissue 10 September 1987https://pubs…