Fe³⁺ and Al solubilities in MgSiO₃ perovskite: implication of the Fe³⁺AlO₃ substitution in MgSiO₃ perovskite at the lower mantle condition

Perovskite in the starting composition of Mg 3 Fe 3+ AlSi 3 O 12 was investigated at 24 and 51 GPa and 2100 K using a laser‐heated diamond anvil cell (LHDAC) and an analytical transmission electron microscopy (ATEM) to understand the solubilities of Fe 3+ and Al into MgSiO 3 ‐dominated perovskite. A single phase of orthorhombic perovskite was formed at 51 GPa and 2100 K and the Fe 3+ AlO 3 bearing perovskite showed no structural change during decompression. The samples synthesized at 24 GPa and 2100 K showed minor amounts of magnesioferrite and stishovite phases in spaces along the perovskite grain boundaries. These results indicate that the solubility of ferric iron incorporated as the Fe 3+ AlO 3 component in MgSiO 3 ‐based perovskite is higher and slightly lower than 25 mole % at 51 and 24 GPa, respectively.