PAMS Seminar: "Understanding Thermodynamics of Critical Metal Materials under Extreme Conditions" by Dr. Xiaofeng Guo

Dr. Xiaofeng Guo
Washington State University
Department of Chemistry

Note: Dr. Guo will also give a Chemistry & Biochemistry Seminar on Wednesday, April 10.

Abstract:

Critical metals, including rare earth elements (REE), U and Th, are in high demand due to their pervasive use in emerging technology and renewable energy applications. Understanding their thermodynamic parameters is crucial for predicting their transport, deposit, and alteration behaviors in relevant geological conditions (e.g., extreme conditions). In our group, we use a set of structural-thermodynamic techniques to in situ probe chemical and physical changes of critical metal materials under elevated pressure and/or temperature conditions. Specifically, high temperature calorimetry and in situ high temperature X-ray diffraction (XRD) were implemented to investigate phase transition and corresponding enthalpies of reaction and mixing. The high pressure structures and equation of states were studied by coupled diamond anvil cell with synchrotron for in situ high pressure XRD, along with density functional theory (DFT). The elastic constants can also be obtained by resonant ultrasonic spectroscopy. By combining these methods, we can obtain more comprehensive thermodynamic parameters for relevant REE mineral phases. In this talk, I will discuss our recent finding on the high pressure structures of zircon, xenotime-type minerals (commonly accommondating REE and actinides), high temperature transitions of REE phosphates, and thermodynamic of mixing of REE phosphate and carbonate mineral phases.

Free