Simultaneous measurements were made of the self-diffusion of oxygen and silicon

in magnesium silicate perovskite. The oxygen diffusivity was some 2 orders of

magnitude higher than the Si self-diffusivity and Fe–Mg interdiffusion in

perovskite:

D (m2/s) = 9.16 x 10−4exp[-501(kJ/mol)/RT]

at 25GPa. Despite this high O diffusivity, the electrical conductivity of the lower

mantle was expected to be dominated by electronic conduction and the present-day

core was likely to be out of redox equilibrium with the mantle.

Self-Diffusion of Oxygen and Silicon in MgSiO3 Perovskite. D.P.Dobson,

R.Dohmen, M.Wiedenbeck: Earth and Planetary Science Letters, 2008, 270[1-2],

125-9