Impact of Inter-site Spin–Orbit Coupling on Perpendicular Magnetocrystalline Anisotropy in Cobalt-Based Thin Films

Realization of magnetic atomic layers exhibiting strong magnetic anisotropy is desired for future magnetic memory applications. Here, the magnetocrystalline anisotropy of Co-based 3d transition-metal thin films is systematically investigated by using first-principles calculations. The computational results predict that large perpendicular magnetocrystalline anisotropy can be achieved by tuning the atomic-layer alignments in Ni–Co thin film. Both hcp- and fcc-like stacking of Co–Ni thin film prefer the perpendicular magnetization direction while the hcp-like stacking is more stable than the fcc-like stacking. We discovered that not only the on-site SOC of 3d elements determines the magnetocrystalline anisotropy energy but also the strong hybridization between these elements plays a constructive role to enhance the perpendicular magnetocrystalline anisotropy.