Tuning the crystalline field leads to giant regulated perpendicular magnetic anisotropy by depositing Bi atom onto the MgO surface

Abstract

Minimizing the size of magnetic units in miniaturized magnetic storage and spintronics inspires great interest to search for nanostructures with giant magnetic anisotropy energy (MAE). Here, we explore the possibility of perpendicular magnetic anisotropy (PMA) at atomic scale using a Bi atom deposited onto the MgO surface (Bi@MgO) by first-principles calculations. We find that Bi@MgO has high stability and large PMA with 204.76 meV. More importantly, the PMA can be effectively regulated by increasing the distance between Bi atom and the substrate, which reaches extremely large MAE of 314.68 meV at h = 2.6 Å. By analyzing the p-orbital-resolved MAE and the density of states of Bi atom, we find the large MAE mainly originates from the contributions of the quasi-degenerate p x/y near the Fermi level and the changing of MAE is mainly caused by the electronic states changing of 6p orbitals of Bi atoms because of the variation of crystal field . The fundamental study provides an idea to control MAE by tuning the crystal field around the magnetic atom. • The Bi atom deposited onto the MgO surface reaches the large PMA with 204.76 meV. • The PMA can be effectively regulated by tuning the crystalline field. • The PMA reaches extremely large MAE of 314.68 meV by regulating. • The large MAE mainly originates from the contributions of quasi-degenerate p x/y . • The changing of MAE is mainly caused by the electronic states changing of Bi atom.