Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
We have used Fermi-surface pressure-derivative measurements at 2 K and singlecrystal and powder x-ray studies as a function of pressure at room temperature to demonstrate that recently published anomalous Fermi-surface and lattice properties of Re${\mathrm{O}}_{3}$ are related to a novel second-order phase transition.…
A theory of non-Ohmic conduction from depinning of charge-density waves by an electric field is presented. It is based on Zener-type tunneling of the charge-density waves across a gap at the Fermi surface that is determined by the pinning frequency. The theory applies to relatively pure specimens for which the pinning…
The observation of band-to-band luminescence from an amorphous solid ($a$-${\mathrm{As}}_{2}$${\mathrm{S}}_{3}$) shows the existence of localized states at energies considerably above the mobility edge.
Two new effects associated with Fr\"ohlich sliding-mode conductivity have been observed in Nb${\mathrm{Se}}_{3}$. First, nonlinear resistance is observed only after a well-defined threshold field is reached. Second, electric fields above the threshold result in noise in the potential difference across a current biased…
Trapped charges related to thermoluminescence (TL) glow peaks appearing at high temperatures (⪆ 500 °C) can be transferred to empty trapping centres producing TL glow peaks at lower temperatures by incidence of UV photons. The phototransferred thermoluminescence (PTTL) produced in this way in a natural CaF2 sample is…
The absorption spectra of thin layers of the non-cubic alkaline earth halides BaCl2, BaBr2, BaI2, SrBr2, BaFCl, BaFBr, BaFI, SrFCl, SrFBr, and of the cubic SrCl2 are measured in the vacuum ultraviolet up to 10 eV. For the mixed halides additionally the reflection spectra of single crystals are measured. Halogen double…
Transmission and photoluminescence spectra are investigated of GaSe1−xTex and Ga1−xInxSe crystals in the temperature range 4.2 to 100 K. It is shown that low temperature radiative recombination in these crystal is mainly due to direct bound exciton decay. In the temperature range 10 K < T < 77 K radiative recombinatio…
Electrical switching in thin selenium films is studied. Devices with two metal electrodes are compared with those having one indium oxide contact. dc, single, and double pulse studies are utilised in conjunction with scanning electron microscopy in an attempt to investigate the structural and compositional changes occ…
Domain configurations in the β-phase of MoTe2 are analysed by electron diffraction and imaging techniques, and related with the α → β phase transition. Structural models are proposed for the orientation variants giving rise to ortho-, meta-, and para-type boundaries, and for translation variants occurring in β-MoTe2.…
The Si ${L}_{1}{L}_{23}V$, Si ${L}_{23}\mathrm{VV}$, and O $\mathrm{KVV}$ Auger transitions in Si${\mathrm{O}}_{2}$ have been measured and compared to calculated line shapes. The measurements were made on thick steam oxides grown on Si (111). The data were corrected for electron loss and spectrometer distortions; the…
The planktonic diatom Eunotia zasuminensis (Cab.) Körner is reported from eight locations in Ontario, Canada. It is previously known from only four other localities in Europe and Africa and from two rivers in the U.S.A. The taxonomy of E. zasuminensis is discussed relative to similar species. Observations on the rudim…
The mean excitation energy of polystyrene has been evaluated from the dielectric function for this organic solid. The result, $I=68.7$ eV, is in good agreement with a value in the literature obtained using the more conventional technique of extracting this parameter from stopping-power data.
The short time moduli of polystyrene, poly(methyl methyacrylate), and polycarbonate have been measured in the glassy state. The main methods used were as follows: (1) The Young's modulus of a strip was derived by extrapolating to infinite length. (2) A bidirectional strain gauge was used for Young's modulus and Poisso…
The growth of films of Pd, Ni, and Cu on amorphous carbon has been studied under ultrahigh vacuum from the lowest coverages detectable to films many atomic layers thick. Since surface diffusion of these metals does not occur on amorphous carbon at room temperature, these metals are present as isolated adatoms at the l…
We have developed a new method to calculate electronic states associated with localized defects. The method yields energy levels, wave functions, and electron charge densities with a precision which is equal to state-of-the-art results for bulk band structure or surface calculations and thus should eventually allow me…
Chalcogenide bulk glasses exhibiting n-type conduction were first prepared by quenching the melts of mixtures of Ge, Se, and Bi2Se3 or Bi. The conditions for obtaining homogeneous glasses were examined, and measurements of resistivity and thermoelectric power were carried out on Ge20Bi10Se70 glass, one of the typical…
The influence of a rigid substrate on the static strain of an adsorbed incommensurate monolayer is discussed. It is shown that the strain energy is independent of relative translation of the two lattices but does depend on their relative orientation. A simple analytic form is given for the minimum energy orientation a…
Energy-band dispersions and electron lifetimes have been determined for both valence and conduction-band states of copper using angle-resolved photoemission with polarized synchrotron radiation in the $5\ensuremath{\le}h\ensuremath{\nu}\ensuremath{\le}35$ eV photon energy range. Dispersion relations for the occupied $…
The thermoelectric power of n-GaAs has been computed at different lattice temperatures and electron concentrations incorporating the band non-parabolicity, the p-function admixture and the effects of electron screening and degeneracy on scattering probabilities. All the relevant scattering mechanisms have been conside…
Time lags to breakdown in n-hexane have been measured in high over-voltages, using approximately 100 ns width rectangular pulses. At a constant field, the time lags are divided into two types, N and B, at a 'critical distance' d. Above d c , Laue plots have almost similar kinked-line characteristics; below d c , a str…