Metallic nature and site-selective magnetic moment collapse in iron oxide Fe₄O₅ at the extreme conditions of Earth's deep interior

Properties of iron oxides at the extreme conditions are of essential importance in condensed matter physics and Geophysics. The recent discovery of a new type of iron oxide, Fe₄O₅, at high pressure and high temperature of Earth's deep interior attracts great interests. In this paper, we report the electronic structure and the magnetic properties of Fe₄O₅ employing the density functional theory plus dynamic mean field theory (DFT+DMFT) approach. We find that Fe₄O₅ stays metallic from ambient pressure to high pressure. The magnetic moments of iron atoms at the three different crystallographic positions of Fe₄O₅ undergo position-dependent collapse as being compressed. Such site-selective magnetic moment collapse originates from the shift of energy levels and the consequent charge transfer among the Fe-3d orbits under compression.