Spin Transitions in Mantle Minerals

摘要: Mantle minerals at shallow depths contain iron in the high-spin electronic state. The crystal-field splitting energy increases with increasing pressure, which can favor low-spin Hence, pressure-driven transitions from to state were proposed as early 1960s, and lower mantle suggested Only past 10 years did experiments calculations prove that transforms lower-mantle pressures. This transition has important consequences for volume, thermodynamics, bonding. In a geophysical framework, would affect dynamics thermochemical of mantle, through combined effects on density, elasticity, element partitioning, transport properties. These observations provide basis new paradigm physics chemistry Earth's lower(most) mantle.