Atomic-layer stacking dependence of the magnetocrystalline anisotropy in Fe-Co multilayer thin films at MgO(001) interface

Abstract Magnetocrystalline anisotropy (MA) and electric-field-induced modification of the MA energy (E-field-induced MA modification) of Co-Fe multilayer thin films at MgO(001) interface with respect to atomic-layer stacking were investigated using first-principles calculations combined with the cluster expansion method. Although the magnetic quantities have very complicated dependence on atomic-layer stacking, we find that there are key short-range atomic-layer stackings. At the MgO interface, a double atomic-layer stacking of Fe on the MgO enhances an interfacial perpendicular MA while there is no role of the short-range stacking in the E-field-induced MA modification where a single Fe atomic-layer at the interface plays a role. The physical origins underlying these trends were subsequently elucidated by band structure calculations.