Magnetodielectric coupling in Mn3O4

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.

6 pages, 7 figures

References in corpus (2)

• Spin current and magneto-electric effect in non-collinear magnets
• Magnetically driven ferroelectric order in Ni${}_3$V${}_2$O${}_8$