报告人简介：

Renata Wentzcovitch is a Professor in the Applied Physics and Applied Mathematics Department in the School of Engineering and Applied Sciences and in the Department of Earth and Environmental Sciences at Lamont Doherty Earth Observatory, Columbia University, USA. She obtained a PhD in Condensed Matter Physics from UC Berkeley. She did postdocs in the Physics Department at Stony Brook University in the US and in the Cavendish Laboratory at Cambridge University in the UK. Until 2016, she was a Professor in the Department of Chemical Engineering and Materials Science at the University of Minnesota. Her research focuses on developing and applying ab initio quantum-mechanical methods to study materials under extreme pressure and temperature conditions of planetary interiors. She is a member of the American Academy of Arts and Sciences, a Fellow of the American Physical Society, American Association for the Advancement of Science. She received the Humboldt Award for Senior US Scientist, the Heraeus Professorship Award of Goethe University Frankfurt, and the Bridgman Award of the International Association for Advancement of Research in High Pressure Science and Technology (AIRAPT). She was Chair of the Division of Computational Physics of the American Physical Society.

报告摘要：

The discovery of the post-perovskite transition in MgSiO₃ provided a compelling explanation for the D'' seismic discontinuity at the base of Earth's mantle. However, subsequent studies showed that iron and aluminum broaden the bridgmanite–post-perovskite transition over too large a pressure interval for it to generate the observed sharp seismic reflector, creating a long-standing paradox.

In this talk, I will show how this paradox is resolved when the transition is treated as part of the complete pyrolitic assemblage rather than as an isolated silicate phase transformation. First-principles thermodynamic calculations combined with phase-equilibrium modeling demonstrate that the Fe²⁺ spin crossover in ferropericlase redistributes iron away from bridgmanite, substantially sharpening the onset of post-perovskite. The coupled evolution of phase proportions, Fe-Mg partitioning, and spin state creates a narrow reaction-relaxed coexistence region with an anomalously soft bulk modulus. These results provide a new thermodynamic framework for reassessing the geophysical manifestations of the post-perovskite transition in the deep mantle.

邀请人：靳常青（Jin@iphy.ac.cn）

联系人：李 天（litian@iphy.ac.cn）