Structure strength and elasticity of planetary materials at very high pressure

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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.