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Re-examining the Verwey transition in Fe3O4

L. Craco·M. S. Laad·E. Müller-Hartmann
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Abstract

Motivated by recent structural data questioning the adequacy of the charge order (CO)/disorder picture for the Verwey transition (at T=T_V) in magnetite, we re-investigate this issue within a new theoretical picture. Using the state-of-the-art LDA+DMFT method, we show that the non-trivial interplay between the B-site octahedral distortions and strong, multi-orbital electronic correlations in the half-metallic state is a necessary ingredient for a proper quantitative understanding of the physical responses across T_V. While weak CO is found to have very small effects on the low-T spectral function, the low-T charge gap and the resistivity jump across T_V are quantitatively reproduced only upon inclusion of CO in LSDA+DMFT scheme. Our results strongly suggest that the Verwey transition is dominantly driven by multi-orbital electronic correlations with associated JT distortions on the B-sublattice, and constitutes a non-trivial advance in attempts to understand the physics of Fe3O4.

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L. Craco, M. S. Laad, E. Müller-Hartmann. 2005-11-16. Re-examining the Verwey transition in Fe3O4. https://arxiv.org/abs/cond-mat/0511390

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