Change of electrical conductivity of olivine associated with the olivine-spinel transition

摘要: Abstract The electrical conductivity σ of (Mg1−x,Fex)2SiO4 was measured under the stable conditions for olivine (α-phase) and spinel phases (β- γ-phases). present measurements cover much lower iron-content olivines (X = 0.28 0.10) higher temperatures (∼ 1000 to 1200°C) than previous works. Conductivity changes associated with phase transitions ( γ α β ) were observed. They ∼ 10 2 at about 1200°C, independent Fe content. These values are significantly smaller those obtained so far iron-rich samples low in activation energy E* slightly by 0.1 eV that 0.8 1.4 eV. It indicates change depends only on temperature. data can be applied condition base Earth's upper mantle. one order magnitude owing olivine-spinel transition is steep increase two orders mantle zone estimated from geomagnetic observations.