Electrical conductivity of enstatite up to 20 GPa and 1600K

The electrical conductivity of ( Mg_0.9 Fe_0.1 ) SiO₃ enstatite has been measured at pressures of 10 -20 GPa and temperatures of 750-1600 K using a Kawai-type multianvil high-pressure apparatus. The experimental results demonstrate that there are two conduction mechanisms, small polaron is the dominant mechanism in the high temperature regions, while proton is in charge of the low temperature regions as water is determined in the recovered sample in this study. On the other hand, we observe a pressure induced phase transition from enstatite to ringwoodite under pressure of 20 GPa by X-ray diffraction. The conductivity of ringwoodite with water at 20 GPa is in good agreement with the available measurements of hydrous ringwoodite.