Establishment of a Material Research Group in High Pressure Materials Synthesis

这项拨款是为了建立一个新的材料研究 亚利桑那州立大学的研究小组。 集团的研究 强调使用高压合成新的固体 国家材料。 正在探索的高压机制包括 1-50使用活塞-气缸装置进行现场研究 相变和材料性能的最大值约为1 兆巴在金刚石砧细胞，压力和温度的倍数 在2000摄氏度下能承受230个单位的铁砧装置 用于合成新材料。 正在研究的材料 包括：（a）氮化物体系中的新晶相， 碱金属和碱土金属氮化物、硫属化物和氧化物 钙钛矿（B）新型玻璃相 纯氮化物玻璃的稳定化、压力诱导的 结晶金属相和共价相的不稳定，和 (c)压力稳定等离子体增强的新型陶瓷相 化学气相沉积前体。 这些新的固态 利用X射线和中子 衍射、电子显微镜、显微拉曼和显微红外 光谱，固态核磁共振光谱， 电子探针化学分析，俄歇电子能谱， 和电子能量损失谱。 理论指导 合成的努力是通过从头量子计算提供的， 力学计算和从头算分子动力学 技术. 材料研究组承担材料研究， 范围或复杂性，通过传统的 个体研究者研究。 通过以下方式促进进展： 一组具有不同背景的调查人员参加了 交互式、协作式研究。

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.