Invited Paper MI+EM-FrM9
Control of Magnetism at the Antiperovskite/Perovskite Interface

Friday, October 26, 2018, 11:00 am, Room 203A

Complex oxide materials with the perovskite crystal structure (ABO₃) are known for their interesting macroscopic physical properties involving the interplay between magnetism, ferroelectricity, and conductivity. Much less explored are the antiperovskite compounds (AXM₃) where the atomic positions of cations and anions are inverted creating unique, wide-ranging properties different from perovskites. Due to the structural similarity, interfaces combining perovskite and antiperovskite compounds can be fabricated, forming a new playground for materials design, where the coupling across the interface may lead to new fundamental properties and functional behavior. Here, based on density-functional calculations, we explore the magnetoelectric effect at the (001) interface between antiperovskite GaNMn₃ and perovskite ATiO₃ (A = Sr and Ba). Bulk GaNMn₃ is an antiferromagnet with the magnetic moments of the Mn ions lying in the (111) planes, forming non-collinear Γ^5g spin configurations with a zero net magnetization ground state. We predict that different from the Γ^5g non-collinear magnetism of the bulk GaNMn₃, strong magnetic moment enhancement and reorientation emerge at the GaNMn₃/ATiO₃ (001) interface, resulting in a sizable net magnetization pointing along the [110] direction. Moreover, switching the ferroelectric polarization of BaTiO₃ leads to reversal of the net magnetization of GaNMn₃. This phenomenon occurs due to the effect of ferroelectric polarization on the magnitude of the antiferromagnetic exchange coupling between the nearest Mn atoms at the interface. Reversal of magnetization by electric means is the holy grail of voltage-controlled spintronics, and thus our results pave a new route to achieve this functionality by exploiting antiperovskite/perovskite interfaces.