Decomposition of ferropericlase (Mg0.80Fe0.20)O at high pressures and temperatures

We have heated ferropericlase (Mg0.80Fe0.20)O to temperatures of over 2300 K at pressures of above 100 GPa to investigate the stability of the solid solution at elevated P, T conditions. The in situ X-ray study in laser-heated diamond anvil cells, as well as X-ray powder diffraction and chemical analysis of recovered samples, show that ferropericlase dissociates to magnesium oxide and ferrous oxide rich components. We demonstrate the importance of the combination of different analytical techniques for studies of solid-state chemical processes at extreme conditions.