Mn2(Fe0.8Mo0.2)MoO6: A Double Perovskite with Multiple Transition Metal Sublattice Magnetic Effects

Transition-metal-only perovskite oxides can introduce additional magnetic functionality with robust magnetoelectric properties but are rare. In this work we prepared a new transition-metal-only perovskite Mn2(Fe0.8Mo0.2)­MoO6 at high pressure and temperature. Uniquely, Mn2(Fe0.8Mo0.2)­MoO6 was discovered as a line phase upon composition modulation that was motivated from the above-room-temperature multiferroic Mn2FeMoO6 corundum phase. It exhibits ferrimagnetic Fe–Mo sublattice (TC = 194 K) and Mn sublattice antiferromagnetic (Tm ∼ 45 K) transitions. Below Tm the two sublattice orderings are coupled and give rise to canted components in both. A first-order field-induced transition is also observed below 45 K. Mn2(Fe0.8Mo0.2)­MoO6 is a Mott variable range hopping semiconductor. These findings for the first time show that either an exotic perovskite or a corundum phase can be achieved by composition modulation besides the pressure effect.