First-principles study on enhanced magnetocrystalline anisotropy of Fe2P-type alloys

Employing first-principles density functional theory calculations, we investigate the effects of Fe-group substitutional elements of Ru and Os on the structural and intrinsic permanent magnetic properties of Fe2P alloy. Our calculations reveal that the presence of Os substitutional atoms improves uniaxial magnetic anisotropy Ku up to ∼3.3 MJ/m3 in Fe1.92Os0.08P, leading to high anisotropy field μ0Ha of 6.5 T and hardness parameter κ of 2, which are significantly higher than the corresponding values in Fe2P phase. This enhancement is attributed to the interplay of the strong spin–orbit coupled Os 5d states and orbital hybridization between 3d and 5d orbital states. Our computational results suggest the feasibility of enhancement on intrinsic permanent magnetic properties of Fe2P-type structures for rare-earth free permanent magnet applications.