Deformation of NaCoF<sub>3</sub> perovskite and post-perovskite up to 30 GPa and 1013 K: implications for plastic deformation and transformation mechanism

Abstract. Texture, plastic deformation, and phase transformation mechanisms in perovskite post-perovskite are of general interest for our understanding the Earth's mantle. Here, analogue NaCoF3 is deformed a resistive-heated diamond anvil cell (DAC) up to 30 GPa 1013 K. The situ state sample, including crystal structure, stress, texture, monitored using X-ray diffraction. A from structure observed between 20.1 26.1 GPa. Normalized stress drops by factor 3 during as result transient weakening transformation. initially develops texture with maximum at 100 strong 010 minimum inverse pole figure compression direction. Additionally, secondary weaker 001 later compression. Texture simulations indicate that initial deformation requires slip along (100) planes significant contributions {110} twins. Following transition post-perovskite, we observe maximum, which evolves follows orientation relationships previously suggested where c axis preserved phases hh0 vectors reciprocal space parallel [010] perovskite, indicates martensitic-like mechanism. comparison past experiments on bridgmanite current results good understand development microstructures within