Materials Literature
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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…
A new microbolometer for far-infrared detection has been fabricated that allows an increase in sensitivity of a factor of 4 over the best previously reported bolometer. By suspending the detector in the air above its substrate a reduction in the thermal conductance out of the device by a factor of 5 has been achieved.…
Angle-resolved photoemission spectra of a black-phosphorus single crystal have been measured with very high angular resolution using He I and Ne I resonance lines. The experimentally determined band structure has been compared with the self-consistent pseudopotential calculations. Some special points and bands with al…
Heterojunctions have been prepared by the reactive rf, sputter deposition of n-ZnO on sputter-etched n- and p-type silicon substrates. Measurements of conductance show typical low-reverse breakdown at 18–25 V and forward currents of 2–10 mA at 3 V, both n-n and p-n diodes rectify. At low forward bias, 0–0.3 V, both ty…
We present a series of measurements of a fluctuating perturbation in the angular correlation of $^{111}\mathrm{Cd}$ in ${\mathrm{In}}_{2}$${\mathrm{O}}_{3}$ powder samples. We analyze the temperature dependence of the associated hyperfine parameters and conclude that this perturbation arises from "aftereffects" follow…
The electrical resistivity of thin gold films deposited on amorphous substrates is found to increase with decreasing film thickness. The temperature-dependent part of the resistivity, however, is independent of the film thickness. This observation cannot be reconciled with existing theories that deal with surface scat…
Hyper-Raman scattering from KTa${\mathrm{O}}_{3}$ is studied to obtain the frequencies and linewidths of the seven optical $\ensuremath{\Gamma}$ phonons with a high degree of accuracy. Particular attention is paid to the soft-mode region below 150 ${\mathrm{cm}}^{\ensuremath{-}1}$. We confirm and extend the data found…
Various experiments which involve the joint application of dc and ac driving fields, $V={V}_{\mathrm{dc}}+{V}_{\mathrm{ac}}cos(\ensuremath{\omega}t)$, are reported for the charge-density-wave (CDW) state of the linear-chain compound Nb${\mathrm{Se}}_{3}$. Steps are observed in the dc $I\ensuremath{-}V$ characteristics…
Thin films of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) develop low electrical resistivity (<10−3 Ω cm) after irradiation with 2-MeV Ar+ ions. Electron microscopy and diffraction show that vacuum-deposited films of this material consist, prior to ion-irradiation, of discrete crystalline grains (∼20–5…
The creation of a field-controlled variation of the index of refraction in a liquid crystal cell has been analyzed and experimentally verified. To obtain a spherical lens utilizing a simple electrode structure and capable of focusing arbitrary incoming polarizations requires four flat nematic liquid crystal cells. Wit…