Origin of the Verwey transition in magnetite: Group theory, electronic structure, and lattice dynamics study

Abstract

The Verwey phase transition in magnetite has been analyzed using the group theory methods. It is found that two order parameters with the symmetries $X_3$ and ${\Delta }_5$ induce the structural transformation from the high-temperature cubic to the low-temperature monoclinic phase. The coupling between the order parameters is described by the Landau free energy functional. The electronic and crystal structure for the cubic and monoclinic phases were optimized using the {\it ab initio} density functional method. The electronic structure calculations were performed within the generalized gradient approximation including the on-site interactions between 3d electrons at iron ions -- the Coulomb element $U$ and Hund's exchange $J$. Only when these local interactions are taken into account, the phonon dispersion curves, obtained by the direct method for the cubic phase, reproduce the experimental data. It is shown that the interplay of local electron interations and the coupling to the lattice drives the phonon order parameters and is responsible for the opening of the gap at the Fermi energy. Thus, it is found that the metal-insulator transition in magnetite is promoted by local electron interactions, which significantly amplify the electron-phonon interaction and stabilize weak charge order coexisting with orbital order of the occupied $t_{2g}$ states at Fe ions. This provides a scenario to understand the fundamental problem of the origin of the Verwey transition in magnetite.

arXiv comment17 pages, 5 figures, 8 tables. Accepted version to be published in Phys. Rev. B

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• Ab initio study of charge order in Fe3O4
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• Investigation of the presence of charge order in magnetite by measurement of the spin wave spectrum
• Brillouin scattering studies in Fe${}_3$O${}_4$ across the Verwey transition

Cited by in corpus (17)

• Spintronic oxides grown by laser-MBE
• Ferroelectricity in multiferroic magnetite Fe3O4 driven by noncentrosymmetric Fe2+/Fe3+ charge-ordering: First-principles study
• Frustration and entanglement in the $t_{2g}$ spin--orbital model on a triangular lattice: valence--bond and generalized liquid states
• Anharmonicity due to Electron-Phonon Coupling in Magnetite
• Short-Range Correlations in Magnetite above the Verwey Temperature
• Strong Effects of Cation Vacancies on the Electronic and Dynamical Properties of FeO
• First-principles determined charge and orbital interactions in Fe${}_3$O${}_4$
• Trimeron-phonon coupling in magnetite
• Verwey transition as evolution from electronic nematicity to trimerons via electron-phonon coupling
• Frenkel pair formation energy for cubic Fe${}_3$O${}_4$ in DFT+U calculations
• Electronic structure and polaronic charge distributions of Fe vacancy clusters in Fe${}_{1-x}$O
• Influence of isolated and clustered defects on electronic and dielectric properties of wustite
• Ultrafast generation of hidden phases via energy-tuned electronic photoexcitation in magnetite
• Polaron physics and crossover transition in magnetite probed by pressure-dependent infrared spectroscopy
• Dual-stage structural response to quenching charge order in magnetite
• Trimeron ordering, bandgap and polaron hopping in magnetite
• Order parameters in the Verwey phase transition