ELECTRICAL CONDUCTIVITY OF THE MAJOR UPPER MANTLE MINERALS
T. Katsura, T. Yoshino, G. Manthilake, T. Matsuzaki
Institute for Study of the Earth's Interior, Okayama University, Misasa, 682-0193, Japan
Keywords: Electrical conductivity, upper mantle, transition layer, olivine, wadsleyite, ringwoodite
Pages: 1139-1145
Abstract
The electrical conductivity of the major upper mantle minerals, namely, olivine, wadsleyite, and ringwoodite, is reviewed in this paper. There are mainly three electrical conduction mechanisms for three upper mantle minerals, namely, hopping, ionic, and proton conductions. The charge carriers for these conduction mechanisms are an electron hole in Fe ion, a vacancy in Mg site, and a proton, respectively. Hopping conduction is the most essential conduction mechanism for the major upper mantle minerals. Because ionic conduction has high activation energy, it becomes a dominant conduction mechanism only at high temperatures. Proton conduction contributes at relatively low temperatures. If the mantle minerals contain a large amount of water (more than 0.1 wt.%), proton conduction can be a dominant conduction mechanism, even at high temperatures.
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