Effect of iron content on the electrical conductivity of Perovskite and Magnesiowüstite assemblages at lower mantle conditions

We have measured the electrical conductivity of (Mg0.76Fe0.24)SiO3 perovskite and of an assemblage of (Mg0.89Fe0.11)SiO3 perovskite + (Mg0.70Fe0.30)O magnesiowüstite at pressures of 45–80 GPa and temperatures from 295 to 3600 K. The apparent activation energy for electrical conduction is 0.24 (± 0.10) eV for the perovskite and 0.20 (± 0.08) eV for the perovskite + magnesiowüstite assemblage. Comparing our present results with those derived previously for Fe‐poor samples, we find that the electrical conductivities of both the silicate perovskite and the perovskite + magnesiowüstite assemblage depend strongly on iron content. Thus the electrical conductivity distribution inside the Earth could provide an important constraint in modeling the composition of the lower mantle.