Phase transition processes and stability domains

A powerful approach for the investigation of thermodynamic conditions in the planetary-core regime is dynamic compression with high-energy lasers. While this technique can achieve planetary core conditions, there are discrepancies between the static and dynamic results that must be resolved to validate its use in planetary core studies. These discrepancies in the iron melting curve have indeed been a source of much debate and several theories suggest that out-of-equilibrium processes occurring during dynamic compression might produce such discrepancies [Boehler 1993, Ahrens 2002, Resseguier 2003, Zaretsky 2009, Anzellini 2013]; similar discrepancies in the phase diagrams of quartz and Bi have been reported [Resseguier 2003, Berterretche 2004, Smith 2008]. The proposed study will establish an unambiguous methodology for interpreting the phase diagram measurements from dynamic compression for planetary core studies. We will do this by studying the time-resolved kinetics of solid-solid transitions and melting.

© R. Smith

Example of a deviation from equilibrium phase boundaries of Bi under ultrafast laser compression.