Enhancing magnetic anisotropy and stability of α′′-Fe16N2 phase by Co and V co-substitution

Abstract

Employing first-principles density functional calculations, we investigate critical effects of V and Co co-substitution on the structural stability and intrinsic magnetic properties of α′′-phase Fe16N2. We demonstrate that only 1 or 2V substitutes per formula unit stabilize the α′′ phase and enhance uniaxial magnetic anisotropy (Ku) up to 1.1 MJ m?3, which is nearly 2 times that of 0.6 MJ m?3 in α′′-Fe16N2. It is further predicted that Ku can even reach up to 1.8 MJ m?3 in Fe12V2Co2N2 with good stability. These results provide an instructive guideline for simultaneous enhancement of the structural stability and energy product in 3d-only permanent magnets.