Materials Literature
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It is pointed out that isotope fractionation as a result of chemical reactions is due to the small zero-point energy differences between reactants and products of isotopically distinct species. Only at temperatures near absolute zero does this energy difference become significant. Favorable conditions for isotope frac…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTVibrational investigations of polyoxometalates. 3. Isomerism in molybdenum(VI) and tungsten(VI) compounds related to the Keggin structureRene Thouvenot, Michel Fournier, Raymonde Franck, and Claude Rocchiccioli-DeltcheffCite this: Inorg. Chem. 1984, 23, 5, 598–605Publication…
Share Icon Share Twitter Facebook Reddit LinkedIn Reprints and Permissions Cite Icon Cite Search Site Citation Rustum Roy, H. J. Leamy, C. W. White, E. N. Kaufmann, R. L. Schwoebel, K. C. Taylor, C. J. Northrup; Materials Research Society. Physics Today 1 February 1984; 37 (2): 87–89. https://doi.org/10.1063/1.2916117…
The temperature dependence of the infrared reflectivity spectra in KNbO 3 is reported for the cubic, tetragonal and orthorhombic phases in a temperature range extending from 300 to 1200K. Spectra have been fitted with a model based on the factorised form of the dielectric function. The temperature dependence of the mo…
The phase diagram of a system of hard ellipsoids of revolution was investigated by means of constant-pressure Monte Carlo simulation. Prolate as well as oblate ellipsoids were considered. The results for the isotherms of the system at several different values of the length-to-breadth ratio are presented. Four differen…
The transition between the incommensurate plane-wave modulation regime and the multisoliton lattice modulation regime is studied by 87 Rb quadrupole perturbed nuclear magnetic resonance in Rb 2 ZnCl 4 . Both phase and amplitude solitons are taken into account in comparing the experimental and theoretical lineshapes an…
Dielectric relaxation measurements are reported in KTaO 3 :Li. Two distinct freezing processes for Li dipoles are identified: freezing of randomly interacting dipoles and locking of polar clusters.
NbTe 4 and TaTe 4 form as tetragonal crystals in which the metal atoms are arranged in linear chains along the c axis, separated by Te 2 pairs. Electronic structure calculations reveal that interchain interactions are much stronger than in the related halogenated compounds of S and Se. Mixing of the Te 2 p sigma * orb…
Multiplicities in the resonances of chemically equivalent carbons, which appear in the solid-state carbon-13 nuclear magnetic resonance spectra of native celluloses, have been examined at high resolution. The patterns of variation are consistent with the existence of two distinct crystalline forms. One form is dominan…
By moans of MC calculations based on the Fröhlich theory of electron–LO-phonon interaction the emission of electrons from the insulating material SiO2 is simulated and proved by special experiments. For thermally stimulated exoelectron emission (TSEE) a mean initial energy Ēi ≈ 0.5 eV above the bottom edge of the cond…
High-resolution x-ray scattering measurements of the nematic to smectic-$A$ transitions in two different homologous series are reported; it is found that the correlation-length exponents ${\ensuremath{\nu}}_{\ensuremath{\parallel}}$ and ${\ensuremath{\nu}}_{\ensuremath{\perp}}$ and the susceptibility exponent $\ensure…
From adiabatic-scanning calorimetric results it is demonstrated that in mixtures of 9CB and 10CB, two compounds of the alkylcyanobiphenyl ($n\mathrm{CB}$) series, the nematic ($N$) to smectic-$A$ ($A$) transition becomes first order for narrow $N$ ranges. From the latent heats a tricritical point is located in the pha…
Photoexcited ${N}_{4,5}{O}_{1}{O}_{2,3}$ Auger transitions for ${\mathrm{La}}^{3+}$ in La${\mathrm{F}}_{3}$, an insulator, are studied with the photon energy tuned through the $\mathrm{La}4d$ to $4f$ resonant excitations. The post-collision interaction between the photoexcited electron and the Auger electron leads to…
The transmittance of an on-blaze plane-grating monochromator has been calculated as a function of wavelength for different spectral orders. The calculations show that higher, undesirable orders can be suppressed by a judicious selection of grating blaze angle and coating material. However, for intense sources, such as…
Self-consistent unrestricted Hartree-Fock calculations are presented for the adsorption of atomic oxygen onto the nickel oxide (100) surface. The perfect surface is shown to be nonreactive, but enhanced binding is found for vacancy sites in the first two atomic layers. Of particular interest is a second-layer anion-va…
A simultaneous stage change and in-plane order-disorder transition is observed in dilute stage-2 Li-intercalated graphite either at low temperature or high pressure. Classical thermodynamics correctly predicts the observed slope of the equilibrium line in the ($P,T$) plane, justifying the Bragg-Williams approximation…
The conformational space renormalization group method is generalized further to describe excluded volume effects in finite molecular weight polymers in the theta point region where contributions from effective three-body interactions become appreciable. The theory builds upon our previous description of the good solve…
Features in reflection high-energy electron-diffraction patterns arising from various types of surface disorder are discussed, with specific examples of each. The relationship between (001)2\ifmmode\times\else\texttimes\fi{}4 and $(001)\ensuremath{-}c(2\ifmmode\times\else\texttimes\fi{}8)$ reconstructions, which are f…
The structural and energetic aspects of high-Miller-index Si surfaces were investigated by studying the (211), (311), and (331) vicinal surfaces. Several types of new structural models for (211) and (311) surfaces were examined. For (211) and especially (311) surfaces, dangling-bond densities appreciably lower than on…
We have calculated the surface impedance of a thin, spatially dispersive, dielectric film deposited on a metal substrate for two commonly used forms of the additional boundary conditions (ABC's) at the film-vacuum and film-substrate interfaces. The reflectivity has been calculated from the surface impedance for freque…