Spin transition of ferric iron in Mg-perovskite

Abstract

Pressure-induced spin transition of ferric iron in Mg_0.85Fe³⁺_0.15Al_0.15Si_0.85O₃ perovskite was examined by X-ray emission spectroscopy (XES) at SPring-8. The obtained XES pattern indicates that the spin state of ferric iron changes from high spin to intermediate spin between 50 and 80 GPa and the intermediate spin state continues up to 113 GPa. This intermediate spin state of ferric iron can be explained by the crystal field splitting energies of 3d electrons of ferric iron at the distorted dodecahedral site in perovskite.