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Recently a computer adapted theory suitable for evaluating the dielectric properties of polar systems has been proposed. It rests on the assumption that the system behaves like a macroscopic dielectric and that the modifications of dipolar interactions do not affect its dielectric constant. In the present paper these…
We present a general discussion of the isoenthalpic–isostress molecular dynamics theories of Andersen and Parrinello–Rahman. The Parrinello–Rahman theory is shown to be applicable to the case of nonlinear elasticity if the reference state of zero strain is taken to be the state under zero stress; this brings the theor…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTQuantitative technique for the determination of the number of unoccupied d-electron states in a platinum catalyst using the L2,3 x-ray absorption edge spectraA. N. Mansour, J. W. Cook Jr., and D. E. SayersCite this: J. Phys. Chem. 1984, 88, 11, 2330–2334Publication Date (Pri…
Highly conductive films of Al-doped ZnO have been prepared by rf magnetron sputtering of a ZnO target with Al 2 O 3 dopant of 1–2 wt% in content added. Films with resistivity as low as 2×10 -4 Ωcm and transmittance above 80% at the wavelength between 400 and 800 nm can be produced on low temperature substrate with a r…
This paper reports experimental studies of the development of bulk optical properties as a function of crystallite size for the inorganic direct gap semiconductor CdS. Small crystallites are synthesized via colloidal chemical techniques, and their optical properties are studied in situ at extreme dilution. The crystal…
Based on a microscopic theory developed recently, a dynamical model of density fluctuations in simple fluids and glasses is proposed and analyzed analytically and numerically. The model exhibits a liquid-glass transition, where the glassy phase is characterized by a zero-frequency pole of the longitudinal and transver…
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…