Renewal-Experimental Studies of Elasticity, Rheology, and Phonon Dynamics of Materials at Pressure-Temperature Conditions of Earth's Mantle and Core

板块构造是上个世纪最重要的科学发现之一，它是板块构造更深层次动力学过程的表面表现。 最近的层析成像和地球动力学研究提供了固体地球的详细三维描述。要解释这些结果，就需要对构成地球深部的真实的物质有更多的了解，这些物质的性质会因极端的P-T条件而发生剧烈变化。 主要特性包括：密度，r（或摩尔体积，V）晶体晶胞参数（a、B、c、a、B、g）体积弹性模量（K）、剪切弹性模量（G）和单晶弹性（cij或sij）作为晶体取向声子态密度（DOS）和声子色散的函数的压缩（VP）和剪切波速（VS）应力下的优选取向剪切强度，蠕变定律，对地球的静态和动态的全面理解取决于我们对这些参数作为压力和温度的函数的知识。 在很长一段时间里，只有r和K的测量可能超过过渡区的压力（25 GPa），大多数测量被认为是侦察性质。因此，地球模型往往是脆弱和有争议的。 由于以前的赠款支持，高压技术的一系列突破终于使人们有可能提出对所有这些性质的研究。 利用这项新技术，目前的赠款支持在高压和高温下对深部地幔和核心材料的弹性，流变学和声子性质进行全面和综合的一系列实验研究。 其结果将用于解决与地球深部内部的组成、结构、动力学和演化相关的主要问题。

Plate tectonics, one of the most important scientific discoveries in the last century, is the surface manifestation of the dynamic processes of its much deeper roots. Recent tomographic and geodynamic studies provided detailed three-dimensional descriptions of the solid Earth. Interpretations of these results require additional knowledge on the real materials that constitute the deep Earth and whose properties are drastically altered by its extreme P-T conditions. Key properties include: Density, r (or molar volume, V) Crystal unit-cell parameters (a, b, c, a, b, g) Bulk modulus (K), shear modulus (G), and single-crystal elasticity (cij or sij) Compressional (VP) and shear wave velocity (VS) as a function of crystallographic orientation Phonon density of state (DOS) and phonon dispersion Preferred orientation under stress Shear Strength, creep law, and deformation mechanismComprehensive understanding of the static and dynamic Earth depends upon our knowledge of these parameters as functions of pressure and temperature. For a long time, only r and K measurements were possible beyond transition-zone pressures (25 GPa) and most measurements were regarded as reconnaissance in nature. Consequently, Earth models are often tenuous and controversial. Resulted from the previous grant support, a series of breakthroughs in high-pressure technology has finally made it possible to propose a study of all these properties. Using the new technology, the present grant supports a comprehensive and integrated series of experimental studies of the elastic, rheological, and phonon properties of deep mantle and core materials at high pressures and temperatures. The results will be used to resolve major problems associated with the composition, structure, dynamics, and evolution of the Earth's deep interior.