Materials Literature
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We report measurements on the electrical- and thermal-transport properties of fluorine-intercalated vapor-grown carbon fibers ${\mathrm{C}}_{\mathit{x}}$F with the carbon-to-fluorine-atom ratio x between 4.1 and 5.8. The electrical resistivity is found to be very sensitive to the fluorine concentration. Indeed, while…
A general theoretical approach to the modeling of several different process steps in fabrication of ion-exchanged channel waveguides is presented. All of the commonly used fabrication processes are included, and the nature of the ion source and the effect of external electric voltage are taken into account. The model…
Dichloromuconate cycloisomerase from Alcaligenes eutrophus JMP 134 was purified to homogeneity. The enzyme has an Mr of about 270,000 as determined by gel filtration and consists of six to eight subunits of identical Mr 40,000 as determined by SDS/PAGE. Mn2+ ions as well as thiol groups are required for activity. A hi…
Diamond crystals and thin films were prepared by thermal decomposition of methane and hydrogen, in the presence of a hot tungsten filament. Raman microspectroscopy investigations were carried out and correlated to scanning-electron-microscopy observations of the crystallization. It is shown that the diamond Raman sign…
A multiple-scattering analysis of low-energy electron-diffraction intensities has been made for the Cu(110)2\ifmmode\times\else\texttimes\fi{}1-O surface structure, a system for which different techniques have recently been providing very different conclusions regarding both the nature of the reconstruction of the cop…
The optical properties of a sample containing several GaAs quantum wells of different widths separated by relatively thick but leaky ${\mathrm{Al}}_{0.3}$${\mathrm{Ga}}_{0.7}$As barriers are investigated at temperatures up to 150 K. Electrical bias, applied using a Schottky gate, tilts the energy bands and results in…
Elastic and inelastic He-atom scattering has been used to measure the surface structure and surface dynamics of the layered transition-metal dichalcogenide 2H-${\mathrm{TaSe}}_{2}$(001) crystal. The results cover temperatures from 60 to 140 K. Below ${\mathit{T}}_{0}$=122 K an incommensurate charge-density wave (CDW)…
CsHSO 4 cristallise dans P2 1 /c avec a=8,214, b=5,809, c=10,984 A, β=119,39 o , z=4; affinement jusqu'a R=0,057 a 296 K (phase basse temperature). La structure est legerement differente de celle etudiee precedemment avec le groupe d'espace P2 1 /m et z=2. La maille est constituee de 2 pseudo-mailles. Deux sortes de c…
Electrochromic, crystalline WO3 films have been deposited on glass substrates at ambient temperature by an oxygen-ion-assisted technique using oxygen ion energies ≥300 eV and oxygen ion to vapor molecule (WO3) ratios, γ≥2.5. After lithiation, the resulting LixWO3 films exhibited >50% reflectivity in the near in…
We report the first full band-structure calculation of the linear optical properties of strained (Si${)}_{\mathit{n}}$/(Ge${)}_{\mathit{n}}$ superlattices on Si(001) substrates for n=2,3,4. We use a semi--ab initio minimal basis orthogonalized linear combination of Gaussian orbitals technique, in conjunction with a li…
The ${\mathrm{Tm}}^{3+}$\ensuremath{\rightarrow}${\mathrm{Tm}}^{3+}$ and ${\mathrm{Tm}}^{3+}$\ensuremath{\rightleftarrows}${\mathrm{Ho}}^{3+}$ energy transfers have been studied in both Tm-doped and (Tm,Ho)-doped indium-based fluoride glasses over a wide temperature range for several dopant concentrations. The regime…
The electronic structure of Pd clusters deposited on polycrystalline graphite has been investigated by x-ray photoemission, Auger spectroscopy, and bremsstrahlung isochromat spectroscopy. Initial- and final-state shifts of energy levels as a function of the average cluster size R are small, but important modifications…
The resistivity and temperature coefficient of resistivity of copper and nickel thin films used as high-density interconnections in hybrid packages have been measured in the temperature interval 298–723 K. The effects of film thickness, deposition conditions, and postdeposition anneal were analyzed in detail. Minimum…
A general Jones matrix representation for an arbitrary pretilt twisted nematic (TN) cell at any given applied voltage is obtained. A simplified Jones matrix representation for the high pretilt TN cell at the field-off state is derived from this general Jones matrix representation. The validity of this simplified repre…
Self-propagating explosive reactions can occur in multilayer thin films. Explosive silicidation in nickel/amorphous-silicon multilayer thin films has been investigated using a combination of high-speed photography, high-speed temperature measurements, plan-view transmission electron microscopy, and thin film x-ray dif…
With use of x-ray standing waves in UHV and synchrotron radiation, the early stages of growth of ${\mathrm{CaF}}_{2}$ on Si(111) were investigated. A new and subtle arrangement of the Si(111)/${\mathrm{CaF}}_{2}$ interface emerges from this study. For deposition at high substrate temperatures, the first monolayer of $…
We have performed an extensive set of first-principles self-consistent-field (SCF) pseudopotential total-energy and force calculations for Si(001)-(2\ifmmode\times\else\texttimes\fi{}2) and -(2\ifmmode\times\else\texttimes\fi{}1) surfaces to arrive at an optimized model for the 2\ifmmode\times\else\texttimes\fi{}1 sur…
The lowest excited electronic state of small CdSe crystallites is calculated within a tight-binding approximation. Two types of crystal shape and a spatially varying dielectric constant are considered. The results are found to compare favorably to recent experiments.
Molecular dynamics computer simulations are reported here for the structures and energies of monolayer and bilayer films of ammonia adsorbed on the basal plane of graphite. A pair-wise additive intermolecular potential function is used that includes electrostatic interactions by distributions of discrete charges withi…
We report the far-infrared through visible photoinduced absorption (PA) spectra of polyaniline in the emeraldine-base and leucoemeraldine-base forms. The direct-absorption spectrum of emeraldine base (EB) has a broad absorption centered at 2 eV (the ``exciton'' band) and an absorption band at \ensuremath{\sim}3.6 eV (…