CaSiO3 Perovskite May Cause Electrical Conductivity Jump in the Topmost Lower Mantle

The electrical conductivity of CaSiO3 perovskite was measured in situ between 17–24 GPa and 1300–2000 K using a multianvil apparatus and Solartron 1260 Impedance/Gain‐Phase Analyzer in the frequency range of 107–1 Hz. The activation energies are 95–100 and 100–120 kJ/mol, and the activation volumes are 0.06 ± 0.08 and −0.46 ± 0.03 cm3/mol, at 1300–1800 and 1800–2000 K, respectively. Conduction under lower mantle conditions may be dominated by the ionic diffusion of oxygen. The electrical conductivity of CaSiO3 perovskite is higher than that of bridgmanite, majoritic garnet, and ferropericlase, the main constituents of the topmost lower mantle. Therefore, CaSiO3‐perovsktie may significantly contribute to the electrical structure of the topmost lower mantle in spite of its relatively small volume proportion.