Simple Molecular Solids at Ultrahigh Pressures

这个项目的目标是利用最新发展的钻石砧座技术，系统地研究简单分子材料在压力诱导下的转变为300 Gpa(3兆巴)以上的静态超高压。这些实验集中在具有代表性的体系中的压力诱导相变，如H2，H2O，CH4，N2，O2，S，稀有气体，以及由这些材料形成的致密分子化合物，以及简单的金属，如Li和Na。新的单晶、多晶和径向X射线方法被用来确定这些体系中100 Gpa以上的晶体结构。将通过光学、同步辐射红外和拉曼光谱测量振动和电子性质，以扩展相图，检查量子和其他动力学效应，并确定不同分子形式的稳定极限。新的高灵敏度磁化率和电阻率方法可以测量超导电性，并识别这些材料中到200-300 Gpa的电子和磁序新状态的其他转变。最后，用于在静态条件下研究致密物质的技术的压力范围将被扩大。这个项目的目标是系统地研究压力诱导简单分子材料向300 Gpa(3兆巴)以上超高压转变的实验研究。这些实验集中在具有代表性的体系中的压力诱导相变，如H2，H2O，CH4，N2，O2，S，稀有气体，以及由这些材料形成的致密分子化合物，以及简单的金属，如Li和Na。将测量振动和电子性质，以扩展相图，检查量子和其他动力学效应，并确定不同分子形式的稳定极限。新的高灵敏度磁化率和电阻率方法允许测量超导电性，并识别在200-300 Gpa压力范围内向新的电子和磁序状态转变。*

9972750HemleyThe goal of this project is the systematic experimental study of pressure-induced transformations of simple molecular materials to static ultrahigh pressures above 300 GPa (3 megabars) using recently developed diamond-anvil cell techniques. The experiments focus on pressure-induced transformations in representative systems such as H2, H2O, CH4, N2, O2, S, rare gases, and dense molecular compounds formed from these materials, as well as in simple metals such as Li and Na. New single-crystal, polycrystalline, and radial x-ray methods are used to determine crystal structures above 100 GPa in these systems. Vibrational and electronic properties will be measured by optical, synchrotron infrared, and Raman spectroscopy in order to extend the phase diagrams, examine quantum and other dynamical effects, and to determine the stability limit of the different molecular forms. New highly sensitive magnetic susceptibility and resistivity methods allow measurements of superconductivity and identification of other transformations to novel states of electronic and magnetic order to 200-300 GPa in these materials. Finally, the pressure range of techniques used to investigate dense materials under static conditions will be extended. %%%The goal of this project is the systematic experimental study of pressure-induced transformations of simple molecular materials to ultrahigh pressures above 300 GPa (3 megabars). The experiments focus on pressure-induced transformations in representative systems such as H2, H2O, CH4, N2, O2, S, rare gases, and dense molecular compounds formed from these materials, as well as in simple metals such as Li and Na. Vibrational and electronic properties will be measured in order to extend the phase diagrams, examine quantum and other dynamical effects, and to determine the stability limit of different molecular forms. New highly sensitive magnetic susceptibility and resistivity methods allow measurements of superconductivity and identification of other transformations to novel states of electronic and magnetic order in the 200-300 GPa pressure range.***