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。
A high resolution study of the defects in the 18R martensite of the Cu-Al alloys enables a detailed analysis of the basal plane stacking faults and two other particular types of nearly planar defects observed in martensite phases. One type of defect is parallel with the martensite habit plane, another type, more frequ…
Complex dielectric constants of KH 2 PO 4 single crystals along the a - and the c -axes have been measured in the temperature range from 2.5 K to 30 K at frequencies between 10 Hz and 20 kHz. Dielectric dispersions with small loss peaks are observed in both directions. The dispersion along the c -axis (dispersion C) i…
Factor group splittings, of common occurrence in the infrared and Raman spectra of crystals, and dispersion, usually encountered in discussions of lattice modes, are shown to be closely related phenomena. Their relationship is elucidated by a model comprising a linear array of four vibrating units. A correlation betwe…
Electrical measurements of n- and p-Pb 1- x Ge x Te have been made between 4.2 K and 300 K. Below 40 K, resistivity exhibits anomalous behaviours similar to the Kondo effect in a dilute magnetic alloy. The anomaly is strongly correlated with the phase transition temperature. The formation of the pseudo-spins and the e…
We report high-pressure Raman measurements of the zone-center phonons in two ferroelectric crystals that closely resemble the $\mathrm{AB}{\mathrm{O}}_{3}$ perovskite crystal PbTi${\mathrm{O}}_{3}$. These crystals are (${\mathrm{Pb}}_{0.22}$${\mathrm{Ba}}_{0.78}$)Ti${\mathrm{O}}_{3}$, i.e., Ba replacing Pb on the $A$…
The initial stages of the interaction of oxygen with an Fe(100) surface have been investigated at 300 K mainly by electron-energy-loss spectroscopy (EELS) with in situ combined low-energy-electron-diffraction, Auger-electron and secondary-electron-emission spectroscopy, and workfunction---change measurements ($\ensure…
We present the results of a systematic investigation of the empty electronic states up to 10 eV above ${E}_{F}$ in the $3d$ and $4d$ transition metals with the use of bremsstrahlung isochromat spectroscopy (BIS). We compare these data to calculations of the unoccupied densities of states. The agreement between theoret…
Cristallisation dans C2/m avec a=6,633, b=8,584 et c=4,546 A, β=102,67°, Z=2; affinement jusqu'a R=0,083 (diffraction RX sur poudre), R=0,040 (diffraction RX sur monocristal) et R=0,051 (diffraction de neutrons sur poudre). Confirmation de l'isomorphisme avec la thortveitite Sc 2 Si 2 O 7 , mais avec un oxygene pourta…
Crystalline Si${\mathrm{Se}}_{2}$ and a series of ${\mathrm{Si}}_{x}{\mathrm{Se}}_{1\ensuremath{-}x}$ clear yellow-orange glasses ($0.33<x\ensuremath{\le}0.4$) were synthesized and studied by Raman spectroscopy. Spectra of crystals were analyzed in terms of the known crystal structure of Si${\mathrm{Se}}_{2}$ where…
Nanometer scale holes and lines have been produced directly in calcium fluoride, aluminium oxide, and magnesium oxide by an intense beam of electrons. There is a threshold beam current density for drilling, and the variation of this with voltage has been studied. Observations using electron energy loss spectroscopy ha…
Surface-sensitive core-level photoelectron spectra are presented for surface oxide phases of Ta and W in the monolayer range. Discrete chemically shifted core levels are observed which are up to 5 times sharper than in bulk oxides. A simple model is proposed for explaining the wealth of corelevel shifts in terms of di…
Trapping of ion-implanted deuterium (D) by lattice defects in copper has been studied by ion-beam-analysis techniques. The evolving depth distribution of D was monitored by using the nuclear reaction D (3He, p) 4He, and the D lattice location was obtained by means of ion channeling. Linear-ramp annealing following a 1…
The fitting of measured optical index data to the Sellmeier dispersion formula, using the variable projection algorithm, is described. Examples of fits obtained by this method to several Schott optical glasses and non-glass materials are given.
Germania glass was prepared from high purity GeO2 powder. Refractive-index dispersion was used to calculate material dispersion and to provide a model for representing the dispersion of GeO2–SiO2 glasses. The wavelength of zero material dispersion is found to be in agreement with theoretical calculations. Modal propag…
The fractions of 15 to 60 keV electrons back-scattered from and absorbed in transparent polycrystalline films of Al and Au have been measured at angles of incidence from 0 degrees , i.e. normal incidence to 80 degrees . Subtracting the sum of both these fractions from unity, the fraction of electrons transmitted throu…
The author's stated purpose in writing this book is to summarize the large number of government‐sponsored research reports on the geochemical aspects of high‐level nuclear waste isolation. Although this book has a 1984 publication date, the majority of the cited documents were published before 1982. Unfortunately, pas…
Photoemission measurements on cleaved NiO(100) identify both the O $2p$ $\ensuremath{\pi}$ valence orbitals and the previously undetected O $2p$ $\ensuremath{\sigma}$ orbitals. An upper limit of 0.8\ifmmode\pm\else\textpm\fi{}0.1 eV is set on the width of the Ni $3d$ ${t}_{2g}\ensuremath{\downarrow}$ emission. A large…
The vibrational excitations in vitreous silica above 150 GHz were investigated at 50, 100, and 290 K by inelastic scattering of cold neutrons. A detailed study of the frequency and wave-vector dependence shows that even at the lowest frequencies only a small part of the scattering is due to acoustic phonons. The type…
Photoemission and bremsstrahlung-isochromat-spectroscopy data on a cleaved NiO single crystal are presented and compared to band- and cluster-theory predictions. In contrast to band-theory predictions the band gap is found to be large but not determined solely by the even larger $d\ensuremath{-}d$ Coulomb interactions…
A fluorescence at 657.7 nm observed for heat-treated optical fibres in a hydrogen atmosphere is reported. The fluorescence intensity is related to the short wavelength loss increase of optical fibres. The origin of the fluorescence is assumed to be defect centres associated with GeO2, or GeO.