Iron-rich Fe–O compounds at Earth's core pressures
Graphical abstract
Oxygen and iron are the most abundant elements on Earth, and their compounds are key planet-forming components. While oxygen is pervasive in the mantle, its presence in the solid inner core is still debatable. Yet, this issue is critical to understanding the co-evolution and the geomagnetic field generation. Thus far, iron monoxide (FeO) is the only known stoichiometric compound in the Fe–FeO system, and the existence of iron-rich FenO compounds has long been speculated. Here, we report that iron reacts with FeO and Fe2O3 at 220–260 GPa and 3000–3500 K in laser-heated diamond anvil cells.
