Epitaxial strain controlled magnetocrystalline anisotropy in ultrathin FeRh/MgO bilayers

Using ab initio electronic structure calculations we have investigated the effect of epitazial strain on the magnetocrystalline anisotropy (MCA) of ultrathin FeRh/MgO heterostructures. Analysis of the energy- and k-resolved distribution of the orbital character of the band structure reveals that MCA largely arises from the spin-orbit coupling (SOC) between dx2-y2 and dxz/dyz orbitlas of Fe atoms at the FeRh/MhO interface. We demonstrate that the strain has significant effects on the MCA: It not only affects the value of the MCA but also induces a switching of the magnetic easy axis from perpendicular on in-plane direction. The mechanism is the strain-induced shifts of the SOC d-states. Our work demonstrates that strain engineering can open a viable pathway towards tailoring magnetic properties for antiferromagetic spintronic applications