The reduction of OH- and S–H absorption bands in unary and ternary germanium sulphide glasses with oxides and hydroxides present in the raw materials and in impure glasses was studied via the chemical reaction of H2and HCl gases at high temperatures. Multicomponent phase equilibria calculations in the Ge–S–H–O–X (X = Cl, I) system were performed to determine the equilibrium partial pressures of gaseous species for removing oxygen and hydrogen from the glasses used for infrared (IR) applications. The effect of carbon on the reduction in oxide and hydroxide absorption bands was also investigated. The absorption characterization was carried out using a Fourier transform infrared reflection spectrophotometer. The IR absorption bands between 1000 and 3700 cm-1 were identified and analyzed. The Boson peaks (BP) in glass samples with two different OH- concentrations were also analyzed. It was found that the presence of OH- enhanced the intensity of Boson peaks. The sites for OH- and shared oxygen with the main [GeS4] 4- tetrahedron structural units in the glass are discussed with respect to the BP and IR absorption analyses. The structure model also identifies the origin of the reduced Rare-earth (RE+3 ) ion solubility (in particular Pr 3+ ions) and its dependence on OH- ion concentrations in GeS2 glasses

We prepared various oxide buffer films on single-crystalline oxide substrates using chemical solution deposition to investigate general interfacial problems of buffer layers for coated conductors, such as epitaxial relationships between buffer material and the substrate. We found that (i) interfaces between the films and the substrates having the same crystal structure were compatible, even in a range of misfit value up to 7%, showing in-plane alignment; however (ii) interfaces between the films and substrates of other combinations of interface structures, with and without occupying tetragonal sites, narrow the range of the epitaxial growth. The former results (i) can be explained by the arrangement of oxygen ions, but for the latter cases (ii), cation arrangement is also important in forming a compatible interface as well as an anion arrangement. The general tendency is largely explained by the ionic arrangement at the interface. The interface structure becomes unstable by the electrostatic repulsive force since the distance between cations at the interface becomes shorter than that in each original crystal structure.

Using infrared absorption and Raman spectroscopy, the structure of SiO2 sol-gel samples containing copper were analyzed as a function of air heat treatments. The weight composition of the samples was 70(SiO2)–30(CuO) and the thermal treatments were carried out in air at various temperatures in the range of 100–600 °C. It was found that the Cu might be incorporated into the SiO2 matrix at least in two ways: forming oxide particles and forming metasilicatelike structures. The copper metasilicate found had the chemical formula, Cu6 [Si6O18] · 6H2O, which is known as dioptase with a thermal stability at temperatures up to 600 °C.

Hydrogenated diamondlike carbon (a-C:H DLC) films were prepared on different substrates by using C2H2–Ar plasma immersion ion processing (PIIP), and their bonding structure was modified by changing deposition parameters of the chamber pressure and the gas composition. The influence of the bonding structure on the properties of the DLC films was investigated by using ion-beam analysis techniques and Raman, infrared, and ultraviolet/visible spectroscopies and by analyzing the measured properties. The increases in density, hardness, and refractive index were found to correlate with the increase of the sp3-bonded structure and the concurrent decrease of both the C–H bonds and the average size of sp2-bonded domains in the films. An optimal combination of optical and mechanical properties was highly dependent on the hydrogen status existing in DLC films that can be adjusted by means of modulation of the synthesis parameters. The prepared DLC films exhibited desirable properties, which included a hardness above 28 GPa, a density above 2.3 g cm−3, a refractive index above 1.94, and band gap energies in the range of 1.8–1.85 eV.

The enthalpies of oxidation, δHox, of oxynitrides YyZr1−yO2x−0.5y−2/3xNx (0.016 < x < 0.2), CayZr1−yO2x−y−2/3xNx (0.03 < x < 0.14), MgyZr1−yO2x−y−2/3xNx (0.146 < x < 0.28), and Zr–O–N (β-type and γ phases) are measured using drop solution calorimetry in molten sodium molybdate (3Na2O · 4MoO3) at 973 K. Linear relations between the enthalpy δHox and nitrogen content were found in all oxynitrides. They indicate that, within the experimental range of nitrogen concentrations, sites occupied by nitrogen ions are energetically equivalent in a given substitutional series. The enthalpies normalized per mole of nitrogen, δHnox, for compounds of Y–Zr–N–O, Ca–Zr–N–O, and Zr–N–O are similar, about −500 kJ/(mol of N). A more exothermic value of δHnox, of about −950 kJ/(mol of N), is seen in Mg–Zr–N–O compounds. The energetics of vacancy formation in zirconium oxynitrides was determined and compared to the energetics of vacancy formation in yttria- and calcia-stabilized zirconia. The enthalpy of vacancy formation (enthalpy of formation relative to end members normalized per vacancy) in zirconium oxynitrides (−190.5 ± 27.0 kJ/mol of Vö) is more exothermic than that in yttria- and calcia-stabilized zirconia (−105 ± 7.2 and −91.4 ± 3.8 kJ/mol of Vö, respectively). This is consistent with the higher tendency for long-range ordering in zirconium oxynitrides compared to stabilized zirconia. Some technological implications of the results are briefly discussed.

A two-color array pyrometer was used to investigate morphological developments on the surface of materials undergoing self-propagating high-temperature reactions. Time sequences of temperature spatial profiles during wave propagation were found to be complex in their nature and dynamics. They contain features that are interpreted in terms of morphological changes during the process. These features include formation of cracks or voids, expansion of the sample, and formation of droplets of metals on the surface. The use of the array pyrometer for determination of the activation energy of the combustion reaction between Zr and NiO is reported.

In Pb(Zr0.4Ti0.6)O3 (PZT) (110-nm-thick) films grown on (001)-oriented LaNiO3 (LNO) (50-nm-thick)/Si(001) films by pulsed laser deposition, the microstructures and various structural properties of the PZT and the underlying LNO films were comparatively studied mainly using synchrotron x-ray scattering experiments. Basically, the PZT films resembled the LNO films in microstructure, crystal orientation, and mosaic distribution. The PZT films, however, showed an isotropic structural order (in- and out-of-plane coherence lengths: 18 and 14 nm) in contrast to the anisotropic order of the LNO films (in- and out-of-plane coherence lengths: 5 and 30 nm). The PZT/LNO/Si systems displayed a good hysteresis characteristic (remanent polarization, 11.8 μC/cm2; coercive field, 36.1 kV/cm). We confirmed that oriented PZT films with reasonable ferroelectric properties can be successfully prepared on properly textured LNO films at a relatively low processing temperature.

Ultrafine grain sizes, of the order of approximately 0.2 μm, may be introduced into Al–Mg–Sc alloys by subjecting the material to severe plastic deformation through the process of equal-channel angular pressing (ECAP). Experiments were conducted to evaluate the influence of the solution treatment temperature on the ductility of an Al–3% Mg–0.2% Sc alloy after ECAP. The results show the highest ductilities are achieved when the solution treatment temperature is within the narrow range of approximately 878 to about 883 K, immediately below the temperature associated with the onset of partial melting. These high temperatures serve to maximize the amount of scandium in solid solution and this leads, on subsequent heating, to an extensive precipitation of fine secondary Al3Sc particles which inhibit grain growth at the higher temperatures. Conversely, solution treatments at temperatures below approximately 878 K give less Sc in solid solution within the matrix and the precipitation of the Al3Sc particles is then insufficient to retain a uniform ultrafine microstructure.