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Magnetodielectric coupling in Mn3O4

R. Tackett·G. Lawes·B. C. Melot·M. Grossman·E. S. Toberer·R. Seshadri
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Abstract

We have investigated the dielectric anomalies associated with spin ordering transitions in the tetragonal spinel Mn$_3$O$_4$, using thermodynamic, magnetic, and dielectric measurements. We find that two of the three magnetic ordering transitions in Mn$_3$O$_4$ lead to decreases in the temperature dependent dielectric constant at zero applied field. Applying a magnetic field to the polycrystalline sample leaves these two dielectric anomalies practically unchanged, but leads to an increase in the dielectric constant at the intermediate spin-ordering transition. We discuss possible origins for this magnetodielectric behavior in terms of spin-phonon coupling. Band structure calculations suggest that in its ferrimagnetic state, Mn$_3$O$_4$ corresponds to a semiconductor with no orbital degeneracy due to strong Jahn-Teller distortion.

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R. Tackett, G. Lawes, B. C. Melot, M. Grossman, E. S. Toberer, R. Seshadri. 2007-03-26. Magnetodielectric coupling in Mn3O4. https://doi.org/10.1103/physrevb.76.024409

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