Materials Literature
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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.
A planar texture of a cholesteric liquid crystal is submitted to a uniaxial steplike strain parallel to the helical axis. Using a time-resolved optical Bragg-scattering technique, we measure the average pitch of the texture (and its dispersion) versus time. We observe a nonuniform hydroelastic dilation, which relaxes…
Synchrotron x-ray diffraction studies of the orientational epitaxy of krypton on single-crystal graphite are reported. The system displays a continuous transition from an aligned to a rotated orientation with increasing mean misfit in a manner predicted by a hexagonal-domain-wall model of the weakly incommensurate pha…
Article Crystal structure of caesium tetroxalate dihydrate, CS(HC2O4) (H2C2O4 ) 2H2O was published on December 1, 1984 in the journal Zeitschrift für Kristallographie - Crystalline Materials (volume 169, issue 1-4).
Interference fringes are observed produced by Mie scattering of laser light from a single microstructure or from a random array of microstructures supported above a reflecting surface. These fringes are the basis of a simple interferometer which can be used to measure distances from thousands of angstroms to centimete…
Calcium oxalate, having a lower solubility product than CaCO3, precipitates on the surface of host carbonate crystals in the presence of oxalate ions. This blocks the carbonate crystals from further interaction, and the process stops when the surface of the mineral grains is fully covered with Ca-oxalate. A kinetic ra…
Abstract Thermogravimetric‐mass spectrometric (TG/MS) and differential scanning calorimetric (DSC) techniques were used in the characterization of oxidative and nonoxidative degradation reactions of a highly crosslinked divinylbenzene/styrene copolymer. When the copolymer was subjected to a temperature‐programmed air…
A design technique for improving the impulse voltage distribution along the axial length of a large aircore power reactor is presented. A set of conducting rings is used to linearize the voltage distribution across the reactor windings. The number, the dimensions and the relative locations of the grading rings are det…
The concentration profile of various dopants (germanium, phosphorus, and fluorine) in preforms and optical fibers has been obtained with a Raman microprobe. A 2-microm spatial resolution was achieved. In the case of germanium and phosphorus, the results agree quite well with those obtained with an electron microprobe.…
Abstract Reactions undergone by leadhillite from the type locality on heating to 1000°C have been followed by DTA, TG, DSC, evolved gas analysis, continuous-heating XRD and IR, and hot-stage microscopy. Intermediate decomposition products were identified by X-ray powder photography. At 80°C, biaxial leadhillite invert…