Materials Literature
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Measurements of the electron spin–lattice relaxation rate are reported for Er3+, Dy3+, and Yb3+ in the cubic host Cs2NaYCl6. Expressions for the anisotropic direct relaxation rates of the respective Γ8 and Γ6 ground states are given in terms of the eleven coupling parameters of the dynamic orbit–lattice interaction fo…
Using a simple Ginzburg-Landau theory which incorporates the crystal symmetry of Nb${\mathrm{Se}}_{3}$, we show that the approximate relation, $2({\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}}_{1}+{\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}}_{2})\ensuremath{\simeq}(1, 1, 1)$, between the two charge-density-wav…
We have measured the temperature dependence of the hydrogen spin lattice relaxation time in the hydride (β, β′, γ, δ) and solid solution phases of the Mg2NiHx system. These gave the temperature ranges of the various phases. The hydrogen diffusion activation energy for the β, β′, γ and δ hydride phases were found to be…
It has been shown that the $D$ band in alkali halides containing ${s}^{2}$ ion (${\mathrm{Tl}}^{+}$, ${\mathrm{In}}^{+}$, ${\mathrm{Ga}}^{+}$, ${\mathrm{Sn}}^{2+}$) is composed of three bands (named ${D}_{1}$, ${D}_{2}$, ${D}_{3}$ in the order of increasing energy). Of the three bands, the ${D}_{1}$ band is the weakes…
The correct normalization of the asymptotic theory for core-level x-ray photoemission spectra of metals has been found. A method for fast convergence of spectra for finite systems as the size becomes large is described. Comparison of asymptotic theory to exact numerical results is made.
The polarized fluorescence band at 3.0 eV which can be produced by photoexcitation of the 6.1-eV $F$ band in high-purity $\ensuremath{\alpha}$-${\mathrm{Al}}_{2}$${\mathrm{O}}_{3}$ has been studied over the temperature range 4.4-300 K. The centroid and zeroth moment of the band remain relatively constant with increasi…
A theory for inelastic Mie scattering from rough metal surfaces or metal sols is proposed. A resonant excitation of a localized dipolar plasmon can enhance the cross section, and experimental data relating to the phenomenon in silver and copper are presented. Two distinct effects are noted. One is inelastic light scat…
We have measured the temperature dependence of the velocity of 10-MHz ultrasonic pulses which were propagated along the layers of the dichalcogenides $2H$-Ta${\mathrm{S}}_{2}$, $1T$-Ta${\mathrm{S}}_{2}$, and $2H$-Nb${\mathrm{Se}}_{2}$. In $2H$-Ta${\mathrm{S}}_{2}$ the plate mode velocity shows little temperature depen…
The organic donor hexamethylenetetrathiafulvalene (HMTTF) forms charge-transfer salts with both tetracyano-$p$-quinodimethane (TCNQ) and its tetrafluoro derivative (TCNQ${\mathrm{F}}_{4}$). We report here the preparation, structure, and conductivity of HMTTF-TCNQ${\mathrm{F}}_{4}$. This salt is found to be isostructur…
We have studied the localized vibrational modes of boron in heavily doped Si using Raman scattering for carrier concentrations of 5\ifmmode\times\else\texttimes\fi{}${10}^{18}$ to 1.5\ifmmode\times\else\texttimes\fi{}${10}^{20}$ ${\mathrm{cm}}^{\ensuremath{-}3}$. The line shapes and positions of the local mode and opt…
The phonon dispersion curves of the fast ionic conductor ${\mathrm{Li}}_{3}$N have been determined in the high-symmetry directions $\ensuremath{\Sigma}$, $\ensuremath{\Delta}$, and $T$ by coherent inelastic neutron scattering at room temperature. The elastic constants ${c}_{11}$, ${c}_{33}$, ${c}_{44}$, and ${c}_{66}$…
We have investigated the single-crystal ionic conductivity of Na5YSi4O12. The conductivity is found to exhibit a thermally activated temperature dependence between 200 and 500 K with activation energies of 0.221 and 0.203 eV parallel and perpendicular to the hexagonal c axis. Room-temperature conductivities were deter…
Single crystals of N${\mathrm{H}}_{4}$${\mathrm{N}\mathrm{i}[{\mathrm{S}}_{2}{\mathrm{C}}_{2}{(\mathrm{CN})}_{2}]}_{2}$. ${\mathrm{H}}_{2}$O have been grown. The single-crystal resistivity in the high-conductivity direction ($\ensuremath{\rho}\ensuremath{\simeq}20$ \ensuremath{\Omega} cm) is the lowest observed for sa…
Valence-band spectra from single crystals of Ir${\mathrm{O}}_{2}$ reproduce the general features of a recent band-structure calculation. Good agreement with the unusual asymmetric core-electron line shapes is obtained by a perturbation-theory treatment of the $d$-electron many-body screening response.
The various effects that can occur when the primary electron energy, ${E}_{p}$, is varied in a reflection-energy-loss experiment are considered. For ${E}_{p}\ensuremath{\ge}100$ eV, the dominant effect is an increase of the electron mean free path with increasing ${E}_{p}$. By performing energy-loss measurements with…
In order to elucidate the structural details of doped polyacetylene (a highly conducting organic polymer), the optical absorption, Raman, and infrared spectra of not only trans-(CH)x doped with iodine, AsF5, and SO3 but also β-carotene doped with iodine and SO3 were studied. The infrared spectra of two kinds of isotop…
Measurements of charging and discharging currents in polyvinylidene fluoride (PVF 2 ) were made over a wide range of fields, temperature, and a limited range of sample thickness and electrode materials. Experimental results suggest that dipolar re-orientation and space charge relaxations are dominant mechanisms for th…
An analysis of the continuum equations of nematic layers subject to large electric or magnetic fields leads to simple extrapolation procedures which allow the infinite field capacitance of the layers to be inferred. For a magnetic aligning field H the reciprocal of the capacitance should be plotted against 1/H, wherea…
The 21 chapters cover: nuclei and isotopes, nuclear mass and stability, decay, cosmic radiation and elementary particles, nuclear structure, nuclear reactions (energetics, mechanisms and models), accelerators and neutron sources, production of radionuclides, thermonuclear reactions and nucleogenesis, naturally occurri…
Shear and longitudinal velocities were measured by the ultrasonic phase comparison method as a function of pressure to 8 kbar on synthetic glasses of basalt, andesite, rhyolite, and quartz composition and on natural obsidian. Velocities of most of the glasses decrease anomalously with pressure, but increasingly more‐n…