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Fluorite-type [Ce.sub.0.5][M.sub.0.5][O.sub.2] and [Ce.sub.0.5][Hf.sub.0.5][O.sub.2] are synthesized by a solution combustion route, and their oxygen release and reduction are investigated. The results have shown the unique role of zirconium, which is different from that of hafnium in the oxygen release/uptake of [Ce.sub.0.5][Zr.sub.0.5][O.sub.2] and [Ce.sub.0.5][Hf.sub.0.5][O.sub.2] solid solutions, as well as the possibility of the formation of highly reduced pyrochlore-II.

The W, V, Ce, Ze, Fe, and Cu metal ion substituted nanocrystalline anatase TiO2 was prepared by solution combustion method and characterized by XRD, Raman, BET, EPR, EPR, XPS, IR TGA, UV absorption, and photoluminescene measurements. Structural studies indicate that the solid solution formation was limited to a narrow range of concentrations of the dopant ions.

Thin films of charge-ordered materials were studied to determine their magnetotransport properties.

A study is conducted on the resistivity, magnetic susceptibility and magnetoresistance of (La0.6Pb0.4MnO3/La0.85MnO(sub 3-delta))n (n = 30 periods) supperlattices fabricated via pulsed laser deposition. Results show that magnetoresistance improves at 285 K caused by the spin-dependent scattering of electrons at the interfaces. The magnetoresistance also depends on the thickness of the magnetic layer.

The benzene***ICl complex was investigated by ultraviolet photoelectron spectroscopy (UVPES) and ab initio and density functional calculations. Electron spectra and calculated orbital energies indicated that donor orbitals are stabilized and acceptor orbitals are destabilized by complexation. Computations indicate an oblique structure for the complex in which the interacting site is a C=C bond center in the donor and iodine atom in the acceptor.

The possibility of using LaNiO3 as contact material with YBa2Cu3O7-x thin films was evaluated by obtaining the contact conductance of the interface between epitaxial LaNiO3 metallic oxide thin films grown on YBa2Cu3O7-x thin films on LaAlO2 substrates. The contact conductance of a LaNiO3-Ag-doped YBa2Cu3O7-x thin film interface which may be utilized in strip line microwave resonators and multilayer heterojunctions was also obtained.

Continuous-wave electron paramagnetic resonance and nuclear magnetic resonance spectrometers revealed distinct line shape differences of rf absorption and field-dependent microwave on the flux-flow regime of the 123 thin films in high-Tc superconductors. Diffraction effects on weak links do not cause losses associated with diffraction reduction of junction currents on weak links and the viscous motion of fluxons.

The intermetallic compound Ni2Mo3N was synthesized and characterized. The nitride, which exhibited both metallic and Pauli-paramagnetic properties, is part of a rare class of compounds that crystallize upon exposure to a filled beta-manganese structure. The structure is composed of corner-shared {NMo6} octahedra in the unit cell, with nickel atoms in 12-fold, pseudo-isosahedral coordination. Three nickel and nine molybdenum atoms surround the structure to form Ni{Mo9Ni3} polyhedra.

High-quality silver doped YBaCuO films deposited by laser ablation on R-plane sapphire devoid of buffer layers show a microwave surface resistance of 530 microohms at 77 Kelvin and 10 GHz, the lowest known for unbuffered sapphire. This value of microwave resistance is explained by improved in-plane epitaxy and a lowered reaction rate between the substrate and the film due to silver doping.