High-Pressure Crystal Chemistry of Earth Materials

地球材料的高压晶体化学

• 批准号: 9973018
• 负责人: Charles Prewitt
• 金额: $ 27万
• 依托单位: Carnegie Institution of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-08-01 至 2003-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9973018&HistoricalAwards=false
• 关键词: Pressure; Crystal; Chemistry; Earth; Materials

Prewitt9973018Research will focus on minerals believed to occur in the Earth's upper mantle and transition zone, but will also involve studies of relevant phases that provide important crystal chemical information. We will study the effects of disorder on equations of state of isomorphs of mantle phases, including silicate spinels, Mg-Fe pyroxenes, Mg-Fe olivines, and Mg-Fe phase B, as well as Fe3+ and Al-bearing high-pressure phases, in order to quantify differences between isostructural and equilibrium equations of state. We will continue our analysis of the dense, hydrous silicates, specifically the effect of adding Fe2+, Fe3+, Al, Ca, Na, and K to explore mineral compositions more relevant to mantle mineralogy. Structural crystallography is undergoing a revolution initiated by the introduction of new x-ray diffractometers coupled with CCD detectors for three-dimensional recording of diffraction patterns. A new Bruker diffractometer with a CCD detector purchased with support from NSF and the Keck Foundation, 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 collect data rapidly at a series of increasing/decreasing pressures and/or temperatures. This and other equipment at the Geophysical Laboratory is available to investigators from other institutions who want to conduct crystallographic experiments, especially at high pressures and temperatures

研究将集中在据信发生在地球上地幔和过渡带的矿物上，但也将涉及提供重要晶体化学信息的相关阶段的研究。我们将研究无序性对地幔相（包括硅酸盐尖晶石、Mg-Fe辉石、Mg-Fe橄榄石、Mg-Fe相B以及含Fe3+和含al高压相）同构态方程的影响，以量化等构态方程和平衡态方程之间的差异。我们将继续分析致密的含水硅酸盐，特别是添加Fe2+， Fe3+, Al, Ca， Na和K的影响，以探索与地幔矿物学更相关的矿物组成。结构晶体学正在经历一场革命，由新的x射线衍射仪和用于三维衍射模式记录的CCD探测器的引入发起。在美国国家科学基金会和凯克基金会的支持下，我们购买了一台带有CCD探测器的新型布鲁克衍射仪，它将使我们能够测量非常小晶体的三维衍射模式，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。地球物理实验室的这台设备和其他设备可供其他机构的研究人员进行晶体学实验，特别是在高压和高温下