Nature of electrical charge carriers in the Earth's lower mantle from laboratory measurements

摘要: Thermoelectric power measurements on a silicate-perovskite and magnesiowustite assemblage at lower-mantle conditions [(Mg0.89Fe0.11)2SiO4 bulk composition 48 GPa temperatures up to 2500 K] yield positive Seebeck coefficient, thus implying that the dominant charge carriers are electrons in conduction band (intrinsic carriers) contribute little electrical conductivity. The present results suggest transport is likely dominated by extrinsic throughout entire mantle and, hence, conductivity can be powerful tool for characterizing minor phases, impurities defect states of Earth's deep interior.