Establishment of a Material Research Group in High Pressure Materials Synthesis

这笔赠款用于在亚利桑那州立大学建立一个新材料研究小组。该小组的研究重点是在合成新型固态材料时使用高压。正在探索的高压模式包括使用活塞-圆柱体压头的1-50千巴范围，在金刚石顶压室中对高达约1兆巴的相变和材料性能的现场研究，在2000摄氏度下能够达到230千巴的压力和温度多压头压头，用于合成新材料。正在研究的材料包括：(A)氮化物系统中的新晶相，如碱和碱土氮化物、硫化物和氧化物钙钛矿；(B)通过压力诱导纯氮化物玻璃的化学稳定，压力诱导结晶金属相和共价相的失稳，以及(C)由压力稳定的等离子体增强化学气相沉积前驱体制备的新型陶瓷相。用X射线和中子衍射、电子显微镜、显微拉曼光谱和显微红外光谱、固体核磁共振光谱、电子探针化学分析、俄歇电子能谱和电子能量损失谱对这些新的固体材料进行了表征。通过从头算量子力学计算和从头算分子动力学技术为合成工作提供了理论指导。材料研究组进行的材料研究的范围或复杂性，通过传统的个人调查员研究是不可行的。通过一组具有不同背景的研究人员参与互动、合作的研究，促进了进展。

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.