Strain-controlled interfacial magnetization and orbital splitting in La2/3Sr1/3MnO3/tetragonal BiFeO3 heterostructures

The electronic and magnetic properties of La2/3Sr1/3MnO3(LSMO)/tetragonal BiFeO3(BFO) heterostructures with the xy-plane biaxial strain were investigated by first-principles calculations. As the xy-plane lattice constant is ranging from 3.619 to 3.921 angstrom, a large interfacial magnetoelectric coupling (IMEC) appears in the LaO/Fe-O-2 and LaO/O-2-Fe models. Particularly, the interfacial Mn in the LaO/O-2-Fe model shows a large spin-down t(2g) orbital splitting at a strain from -2% to 6%, where the maximum splitting energy is 283 meV at 2%. Additionally, the LaO/O-2-Fe model is half-metallic at a strain of 2%, 4%, and 6%. The results demonstrate that IMEC, orbital occupancy, and half-metallicity of LSMO/BFO heterostructures can be effectively engineered by the interfacial coupling and in-plane strain, which paves a way for designing the novel magnetoelectric devices. Published by AIP Publishing.