First-principles determined charge and orbital interactions in Fe${}_3$O${}_4$

Abstract

The interactions between charge and orbitally ordered $d$-electrons are important in many transition metal oxides. We propose an effective energy model for such interactions, parameterized with DFT+U calculations, so that energy contributions of both electronic and lattice origin can be simultaneously accounted for. The model is applied to the low-temperature phase of magnetite, for which we propose a new ground state structure. The effective interactions on the B-lattice of Fe${}_3$O${}_4$ can be interpreted in terms of electrostatics and short-range Kugel-Khomskii exchange coupling. The frustration between optimal charge and orbital orderings leads to a complex energy landscape whereby the supercell for the charge ordering, orbital ordering and ionic displacements can all be different.

15 pages, 4 figures

References in corpus (5)

• Mechanism of the Verwey transition in magnetite
• Resonant X-ray diffraction studies on the charge ordering in magnetite
• Origin of the Verwey transition in magnetite: Group theory, electronic structure, and lattice dynamics study
• Electronic structure of charge-ordered Fe3O4 from calculated optical, megneto-optical Kerr effect, and O K-edge x-ray absorption spectra
• Obtaining correct orbital ground states in $f$ electron systems using a nonspherical self-interaction corrected LDA+$U$ method

Cited by in corpus (4)

• Electronic Orders in the Verwey Structure of Magnetite
• Electric Field Control of the Verwey Transition and Induced Magnetoelectric Effect in Magnetite
• Frenkel pair formation energy for cubic Fe${}_3$O${}_4$ in DFT+U calculations
• Trimeron ordering, bandgap and polaron hopping in magnetite