Materials Literature
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Powder-x-ray-diffraction measurements on siloxene and calculations of the diffraction patterns for the three commonly proposed structures of siloxene (${\mathrm{Si}}_{6}$${\mathrm{H}}_{6}$${\mathrm{O}}_{3}$) clearly show that only a structure with silicon layers is ever observed. The formation of siloxene from ${\math…
We observed by scanning tunneling microscopy (STM) a hexagonal superlattice on graphite with a period of 66 \AA{}. Direct measurement of the angle between lattice vectors confirmed that the superlattice is a Moir\'e pattern caused by a 2.1\ifmmode^\circ\else\textdegree\fi{} rotation of the topmost (0001) plane with re…
The optical study of trivalent 3d transition-metal-oxide compounds (RM${\mathrm{O}}_{3}$) with the perovskitelike structure has revealed the variation of their electronic structure with the 3d element (M) as well as the A-site rare-earth element (R). The crossover of the gap nature from the Mott type to charge-transfe…
The damping of collective electron resonances in clusters which develop into plasmon polaritons at larger sizes is investigated for free, supported, and embedded neutral metal clusters. Embedding of free 2 nm Ag clusters of 2-nm diameter into a ${\mathrm{SiO}}_{2}$ matrix leads to an increase of the width of the reson…
Electron backscattering (EBS) and secondary electron emission (SEE) yield have been measured for bulk carbon with a density of 1.8 g cm -3 , for primary electron energies in the range from 100 to 500 eV and from 12 to 1000 eV respectively. The backscattering results were in agreement with an empirical formula to withi…
Thermoluminescence in LiF:Mg,Ti is frequently described with the Randall-Wilkins model which assumes first-order kinetics. This model fits a measured single glow curve (light output as a function of temperature during heating up the sample) very well. If this model describes the thermoluminescence phenomenon correctly…
The significance of permanent electric dipoles in second harmonic generation is considered with regard to their role in both the non-linear susceptibility and also in the orientation of polar molecules. Under conditions of near-resonance with the first electronic excited state, the susceptibility is dominated by a two…
The crystal structures of the stable, closed complexes of chicken mitochondrial aspartate aminotransferase with the natural substrates L-aspartate and L-glutamate have been solved and refined at 2.4- and 2.3-A resolution, respectively. In both cases, clear electron density at the substrate-coenzyme binding site unequi…
We present a real-space renormalization group (RG) approach to study the electronic properties of the two-dimensional Penrose tilings. This approach is based on a recursive evaluation of the generating function which gives the density of states (DOS) of the system. The RG equations are derived in terms of the inflatio…
Very large single crystals(3 to 8 mm) are observed with the naked eye in the highly deionized colloidal suspensions of monodisperse polystyrene and silica spheres. Deionization is carefully made with the mixed beds of ion-exchange resins more than three weeks. Two kinds of single crystals,i.e., block-like crystals fro…
The cationic distribution and some structure parameters of mixed spinels with a general formula Zn x Co 3-x 0 4 , 0.5<x<1, prepared by thermal decomposition of corresponding zinc-cobalt nitrate precursors, have been studied by means of neutron powder diffraction technique. A partially inverse structure has been determ…
We have performed resistivity and near-ir absorption measurements on ${\mathrm{NiI}}_{2}$ under pressure that strongly suggests that closure of the charge-transfer energy gap is the fundamental cause of the insulator-to-metal transition in ${\mathrm{NiI}}_{2}$. Our findings support the framework proposed by Zaanen, Sa…
The low lying excited states in a system of coupled layers of electrons in a gallium arsenide heterostructure are strongly affected by many-body correlations between the electrons for densities as high as ${\mathit{r}}_{\mathit{s}}$=5. For a layer spacing of less than 100 nm the function Im\ensuremath{\chi}(q,\ensurem…
Quasi-one-dimensional Peierls systems with quantum and thermal lattice fluctuations can be modeled by a Dirac-type equation with a Gaussian-correlated off-diagonal disorder. A powerful new method gives the exact disorder-averaged Green function used to compute the optical conductivity. The strong subgap tail of the co…
It was initially found that CdSb2O6, in which a small part of the Cd ions was substituted with Y ions, has characteristics of a transparent conductor. The electrical conductivity at room temperature of the Y-substituted CdSb2O6 ceramic was larger, by at least 1×100 S cm−1, while that of the nonsubstituted CdSb2O6 was…
Some general relationships have been derived in terms of the unrestricted Hartree-Fock method that define the conditions leading to the breaking of symmetry of one-electron orbitals at oxygen vacancies in oxides of the perovskite family. Numerical calculations of the critical values of relevant parameters have been ca…
The origin of nitrogen acceptor compensation in ZnSe:N has been studied by secondary ion mass spectrometry (SIMS) and infrared absorption (FTIR) measurements. Nitrogen-doped ZnSe layers were grown by atmospheric pressure metalorganic chemical vapor deposition. Ammonia gas was used as a nitrogen source. SIMS analysis h…
We have deposited highly oriented VO2 thin films on R-cut sapphire substrates by the pulsed laser ablation technique. The stabilization of pure VO2 is complicated due to a large number of distinct phases in the vanadium oxide system. As many as 13 different phases ranging from oxygen stoichiometry of V4O to V2O5 can e…
Through thermal treatment of a fluoroaluminosilicate glass codoped with Er3+-Yb3+ at a suitable temperature, microcrystallites were successfully precipitated in the glass matrix but little change was observed in the optical transmission spectra even around the ultraviolet edge, meanwhile the green upconversion lumines…
Photoresist, as one of the most important materials for recording holographic diffraction structures, is treated particularly from the point of view of a control of the development of the surface-relief profile of the grating groove. Primary attention is given to the formation of the desirable profile for the grating…