标题： 冲击响应和行星撞击条件下的MgO相变 显示英文标题

标题： Shock Response and Phase Transitions of MgO at Planetary Impact Conditions

摘要： 月球形成撞击及原始地球的后续演化强烈依赖于这种剧烈碰撞产生的极端条件下材料的性质。我们通过在桑迪亚国家实验室Z-机器上进行的高精度平板撞击冲击压缩实验，以及使用密度泛函理论（DFT）和量子蒙特卡罗（QMC）进行的大规模量子模拟，研究了MgO（地幔中的主要成分之一）的高压行为。综合数据涵盖了从常温常压到1.2 TPa和42,000 K的范围，显示了固-固和固-液相边界。此外，我们的结果表明，在撞击条件下，固相和液相共存超过100 GPa，将完全熔化推至超过600 GPa的压力。完全冲击熔化的高压要求为月球形成撞击所需的相对速度设定了下限。 显示英文摘要

摘要： The moon-forming impact and the subsequent evolution of the proto-Earth is strongly dependent on the properties of materials at the extreme conditions generated by this violent collision. We examine the high pressure behavior of MgO, one of the dominant constituents in the earth's mantle, using high-precision, plate impact shock compression experiments performed on Sandia National Laboratories Z-Machine and extensive quantum simulations using Density Functional Theory (DFT) and quantum Monte Carlo (QMC). The combined data span from ambient conditions to 1.2 TPa and 42,000 K, showing solid-solid and solid-liquid phase boundaries. Furthermore our results indicate under impact that the solid and liquid phases coexist for more than 100 GPa, pushing complete melting to pressures in excess of 600 GPa. The high pressure required for complete shock melting places a lower bound on the relative velocities required for the moon forming impact.