Materials Literature
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With quasielastic neutron scattering the elementary diffusion jump (length and direction) and the jump frequency in bcc \ensuremath{\beta}-Ti single crystals have been determined at temperatures between 1460 and 1580 \ifmmode^\circ\else\textdegree\fi{}C. Supplementary measurements on polycrystalline samples extended t…
For the electronic optical hyperpolarizabilities for molecules γω∥=γZZZZ(−ωσ;ω1, ω2,ω3) and γω⊥=γZXXZ(−ωσ;ω1, ω2,ω3), where Z and X are laboratory axes and ωσ=ω1+ω2+ω3, it is demonstrated that the following relationships exist: (1) γω∥/γ0∥ =1+Aω2L+⋅⋅⋅ , where ω2L=ω2σ+ ω21+ω22+ω23 and A is frequency independent; (2) γω…
The one-dimensional extended Peierls-Hubbard model with half-filled-band electrons is studied in order to clarify the lattice relaxation path of the photogenerated charge-transfer excitation in halogen-bridged mixed-valence metal complexes. The ground and excited states are calculated within mean-field theory for elec…
Optical excitation energies ascribed to the ${\mathrm{Mn}}^{2+}$ center in ZnS:Mn are calculated from Gaussian-based self-consistent-field (SCF) molecular orbitals (MO's) obtained for the tetrahedral ${\mathrm{MnS}}_{4}^{6\mathrm{\ensuremath{-}}}$ cluster at three Mn-S distances in a static external potential, followe…
Films of amorphous ${\mathrm{GeSe}}_{2}$, ${\mathrm{GeSe}}_{3}$, and ${\mathrm{GeS}}_{2}$ have been deposited at various angles of incidence onto appropriate substrates and the nature of the photoinduced oxidation (as monitored by the Ge-O peak at \ensuremath{\sim}800 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ in the…
The dependence of electronic conductivity upon the length (L) of conjugated segments is calculated for conducting polymers for which (1) interruptions in conjugation on neighboring chains are uncorrelated, (2) all chains are equivalent, and (3) intersegment hopping controls chain-direction conductivity. If interchain…
In this article we compare the experimental O 1s x-ray-absorption (XAS) spectrum of CuO with the results of an augmented-localized-spherical-wave (ALSW) calculation with an extended basis set. By extending the basis set in the calculation, we obtain a good overall agreement between experiment and the O 2p unoccupied d…
Electron-spin-resonance studies have been made of the kinetics of \ensuremath{\gamma}-ray-induced defect creation in samples of undensified, low-OH-concentration (<5 ppm) and high-OH-concentration (>1200 ppm) silica and in samples plastically densified by 12.3% (low OH) and 13.8% (high OH). For the oxygen-vacanc…
The temperature and frequency dependence of electrical conductivity (${\ensuremath{\sigma}}_{\mathrm{dc}}$) and the electrical modulus of sodium, rubidium, and Na-Rb mixed alkali germanate and aluminogermanate glasses have been determined for varying alkali concentrations, and [Al]/[Ge] and [Na]/[Rb] ratios. In a few…
Magnetic susceptibility measurements conducted by the superconducting quantum-interference device (SQUID) technique in the temperature range 6--300 K on electrochemically synthesized polypyrrole and polythiophene doped with tetrafluoroborate (${\mathrm{BF}}_{4}^{\mathrm{\ensuremath{-}}}$) are reported. The temperature…
By performing the local-density-functional band calculations, we analyzed the phase stability of nine binary-alloy systems which are composed of Ni, Pd, or Pt as one element and Cu, Ag, or Au as the other. Most of the qualitative aspects of the phase diagrams of these systems are reproduced successfully. It is pointed…
With use of the molecular-dynamics technique, the structural and dynamical correlations in molten and vitreous ${\mathrm{GeSe}}_{2}$ are investigated with an effective interionic potential which consists of Coulomb, charge-dipole, and steric interactions. It is found that the short-range order is dominated by Ge(${\ma…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSurface-enhanced Raman spectroscopyRobin L. GarrellCite this: Anal. Chem. 1989, 61, 6, 401A–411APublication Date (Print):March 15, 1989Publication History Published online22 September 2008Published inissue 15 March 1989https://pubs.acs.org/doi/10.1021/ac00181a001https://doi.…
The relationship between geometry and physical properties of aperiodic structures is investigated by considering the example of the tight-binding Schr\"odinger equation in one dimension, where the site potentials are given by an arbitrary deterministic aperiodic sequence. In a perturbative analysis of the integrated d…
We report exact results for two and three dimensional directed models of polymer chain adsorption–desorption transition in the presence of attracting substrate. A number of properties of this transition are evaluated explicitly. These include the phase diagram, the adsorption fraction and the monomer-density profile.…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSURFACE-ENHANCED RAMAN SPECTROSCOPYCite this: Anal. Chem. 1989, 61, 6, 401A–411APublication Date (Print):March 15, 1989Publication History Published online30 May 2012Published inissue 15 March 1989https://doi.org/10.1021/ac00181a715RIGHTS & PERMISSIONSArticle Views327Altmetr…
Substantial changes in the radial distribution function of amorphous Si films have been observed in neutron-diffraction studies. The spectra indicate changes in short-range order associated with an \ensuremath{\sim}11% modification in the bond-angle distribution width. The results allow the first direct comparison of…
Tin-doped indium oxide (ITO) films have been deposited by RF sputtering an oxide target onto substrates held at different distances from the target surface. The deposition rate is constant up to a target-to-substrate distance of 3.5 cm and decreases with further increase in substrate distance, this distance being asso…
ABSTRACT A series of tests to describe the effect of numerous holes in casing on the mechanical crush resistance has been run in casing and in L-80 steel tube models. The tests were run with big holes and normal hole sizes for perforations in phasings of 0°, 180°, 120°, 90°, and 60°. Shot density was varied in the mod…
Very regularly coiled spring-like fibers of Si3N4 have been obtained from a gas mixture of Si2Cl6, NH3, and H2 at 1200 °C on a graphite substrate on which an iron impurity was painted. The spring-like fibers were amorphous Si3N4 with a circular cross section having a 0.5–1 μm thickness, 3–5 μm coil pitch, 10–15 μm coi…