Structure strength and elasticity of planetary materials at very high pressure

最近在125 GPa和2500 K下发现了新的后钙钛矿相（MgSiO3），对应于地球2700 km的深度，引起了人们的广泛关注。几十年来，钙钛矿阶段一直被认为是地球下地幔的主要阶段，现在，新的发现表明，我们需要重新研究其他重要的地幔阶段，以便更好地了解地球的结构和动力学。本文将在下地幔压力和温度条件下，研究含铁和含al的MgSiO3钙钛矿和CaSiO3钙钛矿相的结构、强度和弹性。高压金刚石砧细胞，连同激光加热系统，将用于这些重要的行星材料的实验研究。此外，新发展的径向x射线衍射方法，结合晶格强度理论，将为高压和高温条件下的材料提供丰富的新信息。由于高压金刚石砧细胞实验的灵活性和多样性，木星卫星和巨行星的气体型和液体型成分也将在极端条件下进行研究，即压力高达200 GPa，温度~2000-3000 K。在这项拟议的研究中获得的结果将有助于更好地理解和模拟地球和其他行星的结构和动力学。

The recent discovery of the new post-perovskite phase (MgSiO3) at 125 GPa and 2500 K, corresponding to 2700 km depth in the Earth, has attracted considerable attention.  The perovskite phase has been believed to be the prevailing phase in the Earth's lower mantle for decades and now, the new discovery reveals that we need to re-examine other important mantle phases in order to better understand the Earth's structure and dynamics.  In this proposal, the structure, strength, and elasticity of Fe- and Al-bearing MgSiO3 perovskite and CaSiO3 perovskite phases at lower mantle pressure and temperature conditions will be studied.  The high-pressure diamond anvil cell, together with a laser heating system, will be used for these experimental investigations of important planetary materials.  Moreover, the newly developed radial x-ray diffraction method, together with lattice strength theory, will provide a wealth of new information on materials under high-pressure and high temperature conditions.   Due to the flexibility and varied capability of high pressure diamond-anvil cell experimentation, gaseous-type and liquid-type constituents of the Jovian satellites and giant planets will also be investigated at extreme conditions, i.e. pressure up to 200 GPa and temperature ~2000-3000 K.  The results obtained in this proposed research will help to better understand and model the structure and dynamics of the Earth and other planets.