High-Pressure Crystal Chemistry of Earth Materials

9805282地球内部的动态历史和现状是由地球材料的性质决定的；对地球过程的详细了解从根本上取决于这些材料在高压和高温下的结构特性。地球物理实验室是在极端条件下开发单晶和粉末样品原位衍射研究技术的先驱。最近，美国国家科学基金会（NSF）资助购买了一台带有CCD探测器的新型衍射仪，这将使我们能够测量非常小晶体的全三维衍射模式，确定影响晶体性能的一系列缺陷的性质，并在一系列增加/减少的压力和/或温度下快速收集数据。具体的实验将集中在硅酸盐、氧化物和硫化物的结构研究，致密含水硅酸盐镁的氢键模型，多阳离子氧化物的阳离子排序，以及各种可以提供地球过程和材料信息的模拟化合物。我们还将继续为想要进行晶体学实验的外部研究人员提供设施和支持，特别是在高压和高温下。

9805282Prewitt/Hazen/FingerThe dynamic history and present state of the Earth's interior result from properties of earth materials; detailed understanding of earth processes depend fundamentally on structural characterization of these materials at high pressures and temperatures. The Geophysical Laboratory has been a pioneer in developing techniques for in-situ diffraction studies on both single crystal and powder samples under extreme conditions. A recent NSF equipment grant supporting the purchase of a new diffractometer with a CCD detector will enable us to measure full three-dimensional diffraction patterns of very small crystals, determine the nature of a range of defects affecting crystal properties, and to collect data rapidly at a series of increasing/decreasing pressures and/or temperatures. Specific experiments will focus on structure investigations of silicates, oxides, and sulfides, hydrogen bonding models for dense hydrous magnesium silicates, cation ordering in multi-cation oxides, and various analog compounds that can provide information about earth processes and materials. We will also continue to provide facilities and support to outside investigators who want to conduct crystallographic experiments, especially at high pressures and temperatures.