Metal-Insulator Transition and the Role of Electron Correlation in FeO2

Abstract

Iron oxide is a key compound to understand the state of the deep Earth. It has been believed that previously known oxides such as FeO and Fe2O3 will be dominant at the mantle conditions. However, recent observation of FeO2 shed another light to the composition of the deep lower mantle (DLM) and thus understanding of the physical properties of FeO2 will be critical to model DLM. Here, we report the electronic structure and structural properties of FeO2 by using density functional theory (DFT) and dynamic mean field theory (DMFT). The crystal structure of FeO2 is composed of Fe2+ and O2 2- dimers, where the Fe ions are surround by the octahedral O atoms. We found that the bond length of O2 dimer, which is very sensitive to the change of the Coulomb interaction U of Fe 3d orbital, plays an important role in determining the electronic structures. The band structures of DFT+DMFT show that the metal-insulator transition is driven by the change of U and pressure. We suggest that the correlation effect should be considered to correctly describe the physical properties of FeO2 compound.

arXiv comment6 pages, 4 figures Corrected typos. Corrected references

References in corpus (7)

• Electronic Structure Calculations with Dynamical Mean-Field Theory: A Spectral Density Functional Approach
• Quantum Monte Carlo Impurity Solver for Cluster DMFT and Electronic Structure Calculations in Adjustable Base
• Dynamical Mean-Field Theory within the Full-Potential Methods: Electronic structure of Ce-115 materials
• A key role for unusual spin dynamics in ferropnictides
• Different response of the crystal structure to isoelectronic doping in BaFe2[As(1-x)P(x)]2 and [Ba(1-x)Sr(x)]Fe2As2
• Metal-insulator transition in NiS${}_{2-x}$Se${}_x$
• Effect of doping and pressure on magnetism and lattice structure of Fe-based superconductors

Cited by in corpus (8)

• Unexpected 3+ valence of iron in FeO${}_2$, a geologically important material lying "in between" oxides and peroxides
• Emergence of quantum critical charge and spin-state fluctuations near the pressure-induced Mott transition in MnO, FeO, CoO, and NiO
• Revealing the complex nature of bonding in binary high-pressure compound FeO${}_2$
• Electronic Spin transition in FeO${}_2$: evidence for Fe(II) with peroxide O${}_2^{2-}$
• Metallic nature and site-selective magnetic collapse in iron oxide Fe4O5 at the extreme conditions of Earth's deep interior
• Site-selective magnetic moment collapse in compressed Fe5O6
• Superionic hydrogen in Earth's deep interior
• Interplay of electronic correlations and chemical bonding in FeN${}_2$ under pressure