This grant is for the establishment of a new Materials Research Group at Arizona State University. The research of the group emphasizes use of high pressure in the synthesis of novel solid state materials. The high pressure regimes being explored include 1-50 kilobar range using piston-cylinder apperati, in-situ studies of phase changes and materials properties up to approximately 1 megabar in diamond anvil cells, pressure and temperature multiple anvil apperati capable of 230 kilobars at 2000 degrees centigrade for synthesis of new materials. The materials being studied include: (a) novel crystalline phases in the nitride system such as alkali and alkaline earth nitrides, chalcogenide and oxide perovskites (b) novel vitreous phases by pressure-induced chemical stabilization of pure nitride glasses, pressure-induced destabilization of crystalline metallic and covalent phases, and (c) novel ceramic phases from pressure stabilized plasma-enhanced chemical vapor deposited precursors. These new solid state materials are being characterized using x-ray and neutron diffraction, electron microscopy, micro-Raman and micro-infrared spectroscopy, solid state nuclear magnetic resonance spectroscopy, electron microprobe chemical analysis, Auger electron spectroscopy, and electron energy loss spectroscopy. Theoretical guidance for the synthetic endeavors is provided through ab initio quantum mechanical calculations and ab initio molecular dynamics techniques. The Materials Research Group undertakes materials research of a scope or complexity that would not be feasible through traditional individual investigator research. Progress is enhanced through a group of investigators with diverse backgrounds participating in interactive, collaborative research.
