Shock Induced Phase Transitions in a High Entropy Rare Earth Sesquioxide, (La_0.2Y_0.2Ce_0.2Pr_0.2Sm_0.2)₂O₃

This presentation will discuss the role of high strain rate and pressure from mechanical shock on the induced phase transitions in the high entropy oxide (HEO), (La_0.2Y_0.2Ce_0.2Pr_0.2Sm_0.2)₂O₃. The facilities at the Dynamic Compression Sector at Argonne National Laboratory enable in situ phase and crystal structure analysis by X-ray diffraction under high strain rate (up to 7 km/s impact velocities) and pressures using a powder gun flyer to impact the HEO target. Analysis of the diffraction data will be used to track crystallographic modification induced by this mechanical shock and its role in the observed phase transitions. In this work, crystallographic phase transitions and amorphization under dynamic (ns) conditions of the above HEO are shown and compared with existing quasi-static compression phase transition measurements.



Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.