Materials Literature
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The crystal structure of the normal phase in {N(CH 3 ) 4 } 2 MnCl 4 has been analyzed for two models: a displacive model and a disordered model. In the former model, the constituent tetrahedra of tetramethylammonium and tetrachloromanganate satisfy a mirror symmetry themselves imposed by the crystal symmetry. In the l…
Measured infrared dielectric function spectra ranging from 300 to 1400 cm−1 for thermally grown silicon dioxide films were studied. The dielectric function spectra were calculated by requiring the calculated spectra to fit to the actual spectra. The peak line shape of the dielectric function can be described by a Gaus…
We investigate the Inherent Structure (IS) dynamics of mean-field finite-size spin-glass models whose high-temperature dynamics is described in the thermodynamic limit by the schematic Mode Coupling Theory for supercooled liquids. Near the threshold energy the dynamics is ruled by activated processes which induce a lo…
The weak interlayer bonding in Bernal graphite induces low-density free carriers and thus low-frequency plasmons (<0.2 eV). Such plasmons reveal themselves as pronounced peaks in the loss spectra and abrupt edge structures in the reflectance spectra. The low-frequency plasmons are very sensitive to changes in temperat…
We report first-principles structural models of surfaces of glassy ${\mathrm{GeSe}}_{2}$ $(g\ensuremath{-}{\mathrm{GeSe}}_{2}).$ The structural properties of bulk and surface $g\ensuremath{-}{\mathrm{GeSe}}_{2}$ are compared with recent experimental data. The first diffraction peaks in the partial structure factors ar…
A new approach to the isolation of the water-soluble factors from nacre without any demineralization is described and examined their effect on fibroblast cells in culture. The soluble matrix in pure water from the nacre of Pinctada maxima was analysed by size-exclusion HPLC. Four fractions (SE1-SE4) of the water-solub…
The simultaneous presence of hydrophilic and hydrophobic interactions could be a driving force in the formation of ordered 2D structures within bis-silanetriols. The synthesis of the first stable examples of these compounds is reported, as well as the structures as determined by X-ray powder diffraction studies (see p…
The synthesis and characterisation of an asymmetric dinuclear gadolinium(III) semiquinonato complex, namely [Gd2(HBPz3)2(dtbsq)4] CHCl3 (1; HBPz3 = hydrotris(pyrazolyl)borate, dtbsq = 3,5-di-tert-butyl-O-semiquinone), is reported. The crystal structure of 1 was determined at room temperature. It crystallises in the tr…
A direct-space strategy, in which global optimization is carried out on the Rwp hypersurface using a genetic algorithm combined with local minimization of Rwp, has been used to solve the crystal structure of the oligopeptide Phe-Gly-Gly-Phe directly from powder X-ray diffraction data.
We study energy spectra, eigenstates, and quantum diffusion for one- and two-dimensional quasiperiodic tight-binding models. As for our one-dimensional model system we choose the silver mean or ``octonacci'' chain. The two-dimensional labyrinth tiling, which is related to the octagonal tiling, is derived from a produc…
A new approach to the isolation of the water-soluble factors from nacre without any demineralization is described and examined their effect on fibroblast cells in culture. The soluble matrix in pure water from the nacre of Pinctada maxima was analysed by size-exclusion HPLC. Four fractions (SE1-SE4) of the water-solub…
Using a many-body approach based on single-particle pseudopotential wave functions, we calculate the dependence of the optical transitions in CdSe nanocrystals on the presence of ``spectator'' electrons or holes. We find that (i) as a result of the different localization of the electron and hole wave functions, the ab…
Fabrication of portland cements commonly depends on X-ray fluorescence (XRF), which measures the elemental compositions. XRF is used to adjust the raw material proportions and to control the process conditions. However, to predict the mechanical strength of the resulting concrete, it is essential to know the phase com…
We describe experiments which demonstrate that carbon atoms introduced into a fused-silica substrate by means of MeV ion implantation can, after suitable annealing, form nanocrystalline diamond. Unlike other methods of creating diamond, the coalescence of the carbon into diamond nanocrystals occurs when the samples ar…
Erbium-doped ZnO (ZnO:Er) thin films were fabricated by the KrF excimer laser ablation technique, which is a useful and simple technique to dope Er atoms on the order of 1020 cm−3 into a host material. As-prepared ZnO:Er films showing strong c-axis orientation with a hexagonal crystalline structure indicate a low elec…
We present a detailed investigation of the surface electronic structure of solid ${\mathrm{K}}_{3}{\mathrm{C}}_{60}$ in connection with its electronic transport properties. We find that the conductivity is extremely sensitive to the K concentration of the surface layer, and that the best-conducting samples with the hi…
Coordination of the pentatopic ligand 3 with AgI leads to the simultaneous self-assembly of two polynuclear architectures: a [4×5] grid-type species 10 and a quadruple-helicate 11, which contain twenty and ten silver ions, respectively. Their structures have been established by X-ray diffraction analysis of the crysta…
An empirical model based on cascade ``quenching'' and epitaxial recrystallization has been developed to describe the accumulation of the amorphous fraction during ion beam irradiation experiments. The model is based on the assumption that the amorphous fraction that remains after the formation of a cascade is related…
Structural models of alkali tellurite glasses, (M 2 O) x (TeO 2 ) l- x with M = Li, Na, K are presented. The glass structure was studied with neutron and X-ray diffraction, and, in the case of sodium, NMR. Real-space models of the glass structure were built using the reverse Monte Carlo algorithm. The distribution of…
The non-reversing heat flow, Δ H nr ( x ) near T g in ternary Ge x As x Se 1 − 2 x glasses is examined by temperature-modulated differential scanning calorimetry. The Δ H nr ( x ) term shows a deep minimum (which is almost zero) in the 0.09 < x < 0.14 range, identified with the intermediate phase , and an increase, bo…