Please use this identifier to cite or link to this item: http://hdl.handle.net/10995/101667
Title: Microscopic toy model for magnetoelectric effect in polar Fe2Mo3O8
Authors: Solovyev, I. V.
Streltsov, S. V.
Issue Date: 2019
Publisher: American Physical Society
Citation: Solovyev I. V. Microscopic toy model for magnetoelectric effect in polar Fe2Mo3O8 / I. V. Solovyev, S. V. Streltsov. — DOI 10.1103/PhysRevMaterials.3.114402 // Physical Review Materials. — 2019. — Vol. 3. — Iss. 11. — 114402.
Abstract: The kamiokite Fe2Mo3O8 is regarded as a promising material exhibiting a giant magnetoelectric (ME) effect at the relatively high temperature T. Here, we explore this phenomenon on the basis of first-principles electronic structure calculations. For this purpose, we construct a realistic model describing the behavior of magnetic Fe 3d electrons and further map it onto the isotropic spin model. Our analysis suggests two possible scenarios for Fe2Mo3O8. The first one is based on the homogeneous charge distribution of the Fe2+ ions among tetrahedral (t) and octahedral (o) sites, which tends to lower the crystallographic P63mc symmetry through the formation of an orbitally ordered state. Nevertheless, the effect of the orbital ordering on interatomic exchange interactions does not seem to be strong, so that the magnetic properties can be described reasonably well by averaged interactions obeying the P63mc symmetry. The second scenario, which is supported by obtained parameters of on-site Coulomb repulsion and respects the P63mc symmetry, implies the charge disproportionation involving the somewhat exotic 1+ ionization state of the t-Fe sites (and 3+ state of the o-Fe sites). Somewhat surprisingly, these scenarios are practically indistinguishable from the viewpoint of exchange interactions, which are nearly identical in these two cases. However, the spin-dependent properties of the electric polarization are expected to be different due to the strong difference in the polarity of the Fe2+-Fe2+ and Fe1+-Fe3+ bonds. Our analysis uncovers the basic aspects of the ME effect in Fe2Mo3O8. Nevertheless, the quantitative description should involve other ingredients, apparently related to the lattice and orbitals degrees of freedom. © 2019 American Physical Society.
Keywords: CALCULATIONS
DEGREES OF FREEDOM (MECHANICS)
ELECTRONIC STRUCTURE
EXCHANGE INTERACTIONS
CHARGE DISPROPORTIONATION
COULOMB REPULSIONS
ELECTRIC POLARIZATION
FIRST PRINCIPLES ELECTRONIC STRUCTURE
GIANT MAGNETOELECTRIC
INTERATOMIC EXCHANGE INTERACTIONS
IONIZATION STATE
QUANTITATIVE DESCRIPTION
IRON COMPOUNDS
URI: http://hdl.handle.net/10995/101667
Access: info:eu-repo/semantics/openAccess
SCOPUS ID: 85075268122
PURE ID: 11348998
4a057a31-3a4d-48f1-95fc-a78d10d79be7
ISSN: 24759953
DOI: 10.1103/PhysRevMaterials.3.114402
Appears in Collections:Научные публикации, проиндексированные в SCOPUS и WoS CC

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