Materials Literature
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When the mean-free path length of conduction electrons in a metal is comparable to the thickness of the specimen d, various kinds of size effects appear. To study these effects, under the cleanest conditions, filamentary crystals—whiskers—are used. At low temperatures conditions under which d are easily achieved in wh…
Normal-incidence reflectivity spectra of 1T-VSe 2 have been measured at room and liquid nitrogen temperatures with E perpendicular to c and E//c, and Kramers-Kronig analysis has been carried out for the E perpendicular to c spectra over the energy range 0.6-14 eV. The formation of charge-density waves at 110K is seen…
Conformal invariance and unitarity severely limit the possible values of critical exponents in two-dimensional systems.Received 31 January 1984DOI:https://doi.org/10.1103/PhysRevLett.52.1575©1984 American Physical Society
A rigorous theory for low-energy scattering in quantum systems in $n$ dimensions, $n>~2$, with general, possibly long-range, interactions is presented. It gives new insights into lowenergy phenomena; e.g., for $n=2$ the controversy around the existence of scattering parameters is resolved. Furthermore, the importan…
Broyden's method (1965) for self-consistent field convergence acceleration, recently used by Bendt and Zunger (1982) in the band-structure calculation of solids, is reviewed and a simpler computational scheme is presented.
The equation of state of perovskite-structure CsCaF 3 has been calculated using Gordon-Kim pair potentials in the quasi-harmonic approximation. Agreement with experimental results is reasonably good for phonon frequencies and equation-of-state properties. Recently, similar calculations for RbCaF 3 were found to be con…
A simple theory of the charging cycle is presented for ovonic switches operating in the relaxation oscillation mode. The theory takes into account the variation of the OFF-state resistance with bias voltage. An analytical expression for the period of oscillation as a function of circuit components and device parameter…
The experimental core-level spectra for the noble metals Cu, Ag, and Au are shown to contain intrinsic satellite features. In the case of Ag, however, the identification is somewhat less certain than for the other two metals. The satellites are interpreted as being due to $d$-valence-electron shakeup processes. This v…
The dimerization equilibrium of deuteroporphyrin IX and of mesoporphyrin IX in aqueous solutions were studied by fluorimetric techniques over the 0.01-1 microM concentration range, where dimerization is the dominant aggregation process. Deuteroporphyrin IX was studied at several temperatures over the range 22-37 degre…
Sol–gel distributions at high conversions, simulated by computer with spatial constraints on the distribution of chain ends, are reported for end-linked tetrafunctional systems. The composition of the sol is found to be uniquely dependent upon the functionality f of the cross linker: for f=4, it mainly consists of lin…
High-resolution electron-energy-loss spectroscopy can be applied to insulators by use of an auxiliary electron gun. Fuchs-Kliewer phonons of the MgO(001) surface were recorded with excellent resolution (27 ${\mathrm{cm}}^{\ensuremath{-}1}$). Specular intensities were analyzed for angles of incidence from 40\ifmmode^\c…
Cristallisation dans P321 avec a=7,958 et c=4,124 A, Z=1; affinement jusqu'a R=0,020. Des colonnes infinies d'atomes Sr a coordination 9 sont placees le long des axes d'ordre 3. Trois molecules H 2 O sont coordinees equatorialement a chaque atome Si tandis que les six autres H 2 O sont egalement liees aux atomes Si ad…
The atomic arrangement in Sr3(FeF6)2 determined by von der Mühll [C. R. Acad. Sci. Paris 278, 713 (1974)] differs from a structure of opposite polarity by atomic displacements of 1.3 Å or less for F and 0.4 Å or less for Sr and Fe. The structure is hence potentially ferroelectric, with an estimated transition temperat…
Raman studies of vitreous B2O3 have been conducted between 8 and 700 K, and as a function of hydrostatic pressure (∼8 kbar) at room temperature. The low temperature Raman spectra exhibit two broad bands at 50 and 137 cm−1. From the temperature dependence of the 50 cm−1 band, it has been concluded that the vibrational…
The infrared reflectivity, the temperature-dependent conductivity, and thermopower of the one-dimensional conductor ${\mathrm{Li}}_{0.82}$[Pt${({\mathrm{S}}_{2}{\mathrm{C}}_{2}{(\mathrm{CN})}_{2})}_{2}$] \ifmmode\cdot\else\textperiodcentered\fi{} 2${\mathrm{H}}_{2}$O, LiPt(mnt), is presented. It undergoes a simple Pei…
The complex dynamical resistivity of high-quality transparent and heat-reflecting indium tin oxide films, prepared by reactive e-beam deposition, was evaluated from spectrophotometric measurements in the 0.25–50-μm wavelength range. These data are explained in detail from a theory encompassing scattering of free elect…
Magnetization measurements for the R6Fe23 (R=Y, Dy, Ho, Er, Tm, Lu) intermetallic compounds and molecular field analyses of the data are reported. A single-sublattice model accurately describes the temperature dependence of the magnetization for Y6Fe23 and Lu6Fe23. Excellent correspondence with the data for the other…
We study the $T=0$ K properties of the electron-phonon system with Coulomb interaction using a two-cutoff renormalization procedure. We find that there exist two regimes. The "classical" regime is characterized by a classical amplitude order parameter and exists when the mean-field gap (pseudogap) $\ensuremath{\Delta}…
The end linking of difunctional poly(dimethylsiloxane) with trifunctional cross linkers in the bulk has been simulated with a computer. A random array of primary chains with a Gaussian end-to-end distribution is generated in an image container on the computer. By joining chain ends at nearby junctions, inter- and intr…
We have discovered a low-lying cyclic isomer of Si–C–C which is best described as a three-membered ring with a weak carbon–carbon triple bond. In these theoretical studies a double zeta plus polarization basis set was used initially. At the self-consistent-field (SCF) and two-configuration (TC) SCF levels of theory th…