Materials Literature
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Field emission from localized narrow bands above the Fermi level (${\mathit{E}}_{\mathit{F}}$) are obtained in two nanometer-scale systems: gold nanoclusters deposited on W support tips and nanotips that are W nano-scale protrusions formed on W support tips. The shift of localized bands was used as a probe of the tunn…
Electroluminescence (EL) in gold-coated porous silicon has been studied under pulse excitation. The room temperature EL is independent of ambient, unlike photoluminescence (PL). It decreases after 30 min annealing treatments, disappearing after about 480 °C, whereas the PL from either a similar or the same sample, obs…
The chemical oxidation of hydrogen-terminated silicon (111) surfaces in water was studied in situ with Fourier transform IR spectroscopy in the multiple total internal reflection mode. On the basis of measurements of the absorbance of the Si-H and Si-O-Si vibrations as a function of time it is concluded that reactions…
Structural and electrical properties of rf magnetron-sputtered Ba1−xSrxTiO3 thin films (x=0, 0.25, 0.5, 0.75, 1) on indium-tin-oxide-coated glass substrate were studied. The dense Ba1−xSrxTiO3 thin films sputtered from five different targets at the deposition temperature of 550 °C had individual orientations. The resu…
The paper deals with optical second-harmonic generation in a medium absorbing the second-harmonic radiation, and where phase matching between the fundamental and second-harmonic radiation is not necessarily achieved. We first take the waves to be in the form of traveling waves, and describe the damping of the fundamen…
We report x-ray photoemission, UV photoemission, and bremsstrahlung isochromat spectra of TiO with ordered vacancies in both Ti and O sublattices and of the series ${\mathrm{TiO}}_{\mathit{x}}$ (0.8x1.3) containing disordered Ti and O vacancies. The details of the electronic structure are discussed in comparsion to ba…
Novel compounds RE6Fe13X (X=Cu, Ag, Au, Zn, Cd, Hg) have been synthesized by arc melting (Cu, Ag, Au) or by reaction sintering (Zn, Cd, Hg), followed by heat treatment at 550 or 600 °C up to 350 h in evacuated silica capsules. From room temperature x-ray powder diffraction analyses the alloys were found to crystallize…
Absolute measurements of the photoabsorption coefficient of Mg, Al, and Si from 25 eV up to the ${\mathit{L}}_{3}$ absorption edge are presented. Transmission measurements were performed on free-standing thin films using a laser-produced plasma source. The surface oxide is corrected for by taking the ratio of the abso…
The sumrules for X-ray absorption and photoemission [Thole et al ., Phys. Rev. Lett. 68 (1992) 1943; 70 (1993) 2499] which relate the integrated signals of the magnetic circular and linear dichroism to the orbital magnetic moment and quadrupole moment are generalized to point group symmetry. The polarization dependenc…
A simple quantum-sphere model for small metallic particles of arbitrary size embedded in nonabsorbing dielectric media is used to compute the real and imaginary parts of the dielectric function. The quantum confined electrons can be considered as nearly free electrons but having discrete energy levels. The dielectric…
An experimental study of the local electronic structure of Ce-doped yttria (2% and 5% at.) was performed using photoelectron and x-ray-absorption spectroscopies (XPS and XAS). The local atomic arrangement in the solid solutions is well represented by an eightfold oxygen coordination around Ce atoms, with a Ce-O distan…
The swelling pressure of randomly crosslinked polymer networks is related to the structural properties of the crosslink topology. Using the assumption that the network structure exhibits fractal properties within the correlation length ξ, a scaling relation between the swelling pressure and the polymer volume fraction…
The symmetry properties of chiral monolayered carbon nanotubes, along with the method of zone-folding, are used to study their electronic and lattice properties. The energy bands and phonon modes are classified according to the irreducible representations of the 1D periodicity of the chiral nanotubes.
First-principles methods are used to study diamondlike amorphous carbon. Several structural models are introduced, and the topological, electronic, and vibrational properties are discussed. We explore the nature of defects in the amorphous network, and particularly the atomistic origin of the virtually defect-free opt…
A systematic study is presented on the optical and structural transformations induced in amorphous Ge1−xSbx alloys with Sb contents in the 0.71≤x≤0.91 range by irradiation with 250 ns laser pulses. The results show that only those films richer in Sb than the eutectics (x=0.85) show appreciable optical contrast upon ir…
The optical spectroscopic properties of Mn5+ doped into ten host lattices have been studied. The influence of both chemical variation [phosphates(V), arsenates(V), and vanadates(V)] and structural variation (spodiosites, apatites, and Li3PO4-type salts) on the luminescence properties is studied in detail. By varying t…
The angular dependence of magnetic Barkhausen noise (MBN) on eight surfaces through the thickness of a 2% Mn steel pipeline sample was investigated. The MBN signal was analyzed by integrating the square of the MBN voltage signal with respect to the time axis. The resulting value, referred to as the MBN energy signal,…
The localized character of the 3d electrons in the antiferromagnetic oxides NiO(100) and CoO(100) has been studied with electron energy-loss spectroscopy at primary energies between 20 and 1200 eV. The spectra of both charge-transfer compounds exhibit weak but sharp loss structures within the insulating gap region due…
Using time-resolved digital video microscopy, we have tracked the reemergence of order in charge-stabilized colloidal crystals which have been shear melted into isotropic fluids. Crystallization is heterogeneously nucleated by the smooth walls of the sample container. This process is analogous to the solidification of…
The $^{5}$${\mathit{D}}_{0\mathrm{\ensuremath{-}}}^{7}$${\mathit{F}}_{0}$ transition mechanism has been investigated for the ${\mathrm{Eu}}^{3+}$ ion in two kinds of oxide glasses, polyvinyl alcohol film, and ${\mathrm{Y}}_{2}$${\mathrm{O}}_{2}$S crystal powder, from the analysis of the laser-induced fluorescence spec…