Theoretical study on the magnetic anisotropy of monolayer iron from Orbital Selective External Potential calculations

Abstract Magnetocrystalline anisotropy energy is the core concern in the field of magnetic storage theory. This study explored the theoretical mechanism of magnetocrystalline anisotropy energy of monolayer iron with the change of strain by using an Orbital Selective External Potential (OSEP) method. It is found that magnetocrystalline anisotropy energy of monolayer iron changes linearly with the strain through first principles calculation. We predict the contribution of 3 d z 2 orbital using matrix-analysis. Particularly, we utilize the Orbital Selective External Potential shift the energy levels of 3 d orbitals, observing the occupation number influence on magnetocrystalline anisotropy energy. As a result, we confirmed the main contribution of 3 d z 2 orbital. It is the first application of OSEP method in solving the strain effect of magnetocrystalline anisotropy in 3d ferromagnet systems. This research will help understand the theoretical mechanism of magnetic memory devices based on spintronics.