Cation, magnetic, and charge ordering in MnFe₃O₅

The recently-discovered high pressure material MnFe₃O₅ displays a rich variety of magnetically ordered states on cooling. Fe spins order antiferromagnetically below a Néel transition at 350 K. A second transition at 150 K marks Mn spin order that leads to spin canting of some of the Fe spins and ferrimagnetism. A further transition at 60 K is driven by charge ordering of Fe²⁺ and Fe³⁺ over two inequivalent Fe sites, with further canting of all spins. Electrical resistivity measurements reveal semiconducting behaviour in MnFe₃O₅ with a change in activation energy at 285 K.