Self-diffusion of oxygen and silicon in MgSiO3 perovskite.
EARTH PLANET SC LETT
125 - 129.
We present results of simultaneous measurements of self-diffusion of oxygen and silicon in magnesium silicate perovskite. Oxygen diffusion is similar to 2 orders of magnitude faster than Si self-diffusion and Fe-Mg interdiffusion in perovskite, with D-0 = 9.16 x 10(-4) (+0.16/-9.2 X 10(-6)) m(2)/s and Q = 501 +/- 80 kJ/mol at 25 GPa. Despite this high 0 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. (C) 2008 Elsevier B.V. All rights reserved.
|Title:||Self-diffusion of oxygen and silicon in MgSiO3 perovskite|
|Keywords:||MgSiO3 perovskite, O diffusion, Si diffusion, lower mantle, chemical equilibration, high-pressure, ULTRALOW-VELOCITY ZONES, CORE-MANTLE BOUNDARY, ELECTRICAL-CONDUCTIVITY, ALUMINOUS PEROVSKITE, POST-PEROVSKITE, IRON, DEFECTS, ORIGIN, EARTH, GPA|
|UCL classification:||UCL > School of BEAMS > Faculty of Maths and Physical Sciences > Earth Sciences|
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