Self-diffusion of oxygen and silicon in MgSiO3 perovskite

We present results of simultaneous measurements of self-diffusion of oxygen and silicon in magnesium silicate perovskite. Oxygen diffusion is ~ 2 orders of magnitude faster than Si self-diffusion and Fe-Mg interdiffusion in perovskite, with D0 = 9.16 × 10− 4 (+ 0.16 / − 9.2 × 10− 6) m2/s and Q = 501 ± 80 kJ/mol at 25 GPa. Despite this high O diffusivity, however, the electrical conductivity of the lower mantle will be dominated by electronic conduction and the present-day core is likely to be out of redox equilibrium with the mantle.