Magnetic, structural, and magnetocaloric properties have been investigated for a solid-solution system, Fe1-xMnxV2O4 (0.0≤x≤1.0) with a spinel structure. As orbital-active Fe2+ ions are partially substituted with orbital-inactive Mn2+ ions, various interactions, such as the Jahn-Teller interaction, spin-orbit coupling, and the exchange interaction, compete with each other, giving rise to a rich magnetic and structural phase diagram. The magnetocaloric effect exhibits two peaks as a function of temperature for x≤0.9, associated with a higher-temperature ferrimagnetic transition, and with a lower-temperature concomitant spin-canting and orbital-ordering (mostly lattice-structural) transition of the V site. The large magnetocaloric effect as observed in MnV2O4 can thus be attributed to the sum of the entropy changes upon the merged phase transition at TN1∼TN2.
|Physical Review B - Condensed Matter and Materials Physics
|Published - 2014 Mar 31