Materials Literature
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Neon, argon, and xenon bubbles in aluminum have been investigated by means of electron-energy-loss spectroscopy and transmission electron microscopy. The density and pressure in the bubbles were determined from the pressure shift of the $^{1}S_{0}\ensuremath{-}^{1}P_{1}$ transition of the rare gases as well as from an…
A one‐step synthesis of a new sulfur‐containing compound, L‐α‐amino‐β‐thio‐ϵ‐caprolactam from L‐cysteine methyl ester and 2‐chloroethylamine has been described. This intramolecular cyclic amide of S ‐(β‐aminoethyl)‐L‐cysteine serves as a good substrate for α‐amino‐ϵ‐caprolactam racemase. L‐α‐Amino‐β‐thio‐ϵ‐caprolactam…
The authors have measured the low-temperature thermal conductivity of unusual geometry sapphire bars that have undergone various surface treatments. They show that after careful surface polishing a ten-fold enhancement over the correctly calculated Casimir limit is possible, and that the phonon specular reflection coe…
Intrinsic paramagnetic defects have been detected by ESR measurements in tetrathiafulvalene -$p$- chloranil single crystals, associated with the neutral-to-ionic phase transition at ${T}_{c}=84$ K. Two kinds of paramagnetic species are identified with delocalized spins propagating on either donor or acceptor sites. To…
The active site of the aspartic proteinase, endothiapepsin, has been defined by X-ray analysis and restrained least-squares refinement at 2.1 A resolution with a crystallographic agreement value of 0.16. The environments of the two catalytically important aspartyl groups are remarkably similar and the contributions of…
Electrical conductivity and thermoelectric power are measured in the temperature range 30 to 700 °C on iron-nickel mixed oxide samples containing upto 5 mol% NiO, sintered at different temperatures (1050 t o 1300 °C). The plot of log σ vs. 1/T always shows two straight lines, the slope of the higher temperature region…
UV optical absorption and IR transmittance of Czochralski grown Gd3Ga5O12, garnet single crystals are investigated. Transitions of Gd3 from the 8S7/2 ground state to the 6P, 6L and 6D states are detected. With increasing Ca content a broad band at 29400 cm−l is observed. In the IR spectra the shift of the absorption e…
We have studied the magneto-optical properties of the ${\mathrm{Ga}}_{x}{\mathrm{In}}_{1\ensuremath{-}x}\mathrm{Se}$ system in the indium-rich and gallium-rich regions near the fundamental band gap by wavelength-modulation spectroscopy at 10 K with the electric vector $\stackrel{\ensuremath{\rightarrow}}{\mathrm{E}}$…
Two general types of energy-dependent cross-section variations are demonstrated for inverse photoemission: (i) an atomic effect based on the spatial extent of the wave function and (ii) a solidstate effect caused by peaks in the Fourier spectrum of bandlike states. As examples, data are shown on the photon-energy depe…
The Rayleigh–Brillouin spectrum of 2,4-dimethyl pentane, 2,4,6-trimethyl heptane, 3,5-dimethyl heptane, 2,2,4,4-tetramethyl pentane, and 2,2,4,4,6,6,8,8-octamethyl nonane was measured as a function of temperature from well above the Brillouin linewidth maximum down to the glass transition region. Brillouin splittings…
We report on high-resolution total-yield measurements of the Cu ${L}_{2,3}$ absorption edge in ${\mathrm{Cu}}_{2}$O using the JUMBO monochromator at the Stanford Synchrotron Radiation Laboratory. Care was taken to prepare the surface of a well-characterized single crystal, rather than use oxidized copper. A comparison…
Angle-resolved photoemission with synchrotron radiation was applied to Pb(111) in order to determine the electronic band structure of Pb. The $\ensuremath{\Gamma}L$ direction was mapped out by recording normal-emission photoelectron spectra. Band energies at several symmetry points in the Brillouin zone were obtained…
A gradient-index antireflection coating spanning the 0.6–12.6-μm wavelength range for a ZnSe substrate was designed, fabricated, and tested. The index profile used was a fifth-order polynominal that smoothly matches the substrate. The coating was fabricated using a discrete layer approximation for the gradient-index d…
We report theoretical investigations on the electronic structure of ideal, defect-free surfaces of rutile (${\mathrm{TiO}}_{2}$). The (110), (001), and (100) faces are studied, and for each face, several models are examined, which correspond to different surface atomic compositions. The bulk electronic structure is de…
The diffusion of As in polycrystalline silicon films subjected to rapid thermal annealing has been studied using sheet resistance and Rutherford backscattering. The polycrystalline Si films were deposited on oxidized silicon wafers, implanted with As, and annealed with a Varian IA-200 isothermal annealer. Infrared rad…
Soft-x-ray emission ($K\ensuremath{\beta}$ emission) and absorption ($K$ absorption) spectra of a black P single crystal polarized along each crystalline axis are presented for the first time. The experimental results indicate (1) the upper part of the valence band near the Fermi level is largely contributed by the $3…
The electron density distribution in Fe–phthalocyanine is mapped using a set of accurate diffraction data collected at 110 K. Structural results are in agreement with an earlier room-temperature determination. Deformation electron density maps show a deficiency of the Fe electron density along the axis perpendicular t…
The character of the first unoccupied band in the graphite intercalation compound ${\mathrm{LiC}}_{6}$ is examined. Based on a framework of interacting nonorthogonal states, an analysis of previous band-structure results shows that this band can be interpreted as a hybrid of Li $2s$ and graphite interlayer states.
The temperature dependence of the birefringence and magnetic field induced effects were studied on thin films of mixtures of potassium laurate, 1-decanol, and D2O. The selected mixtures have a small biaxial nematic range between two uniaxial nematics. The biaxial–uniaxial nematic phase transitions are second order and…
Reflectivity measurements in the far-infrared region irrefutably show the consequence of the Peierls instability in the blue bronze ${\mathrm{K}}_{0.3}$${\mathrm{MoO}}_{3}$ system. At 5 K, a very strong polarization-dependent phonon spectrum is observed: At photon energies below 8 meV, a giant, nearly undamped structu…