Magnetic structures and magnetic anisotropy of Mn3−x Fe x Sn studied by first-principles calculations

Abstract

Aiming at clarifying the structures and magnetic anisotropies of kagome Mn3−x Fe x Sn crystal over the wide range of x, we theoretically investigate the x-dependence of lattice parameters and bond lengths of their six magnetic phases by the first-principles calculations, and discuss their stabilities. Under the virtual crystal approximation at the Mn/Fe sites with a composition increment of Δx = 0.25, we find the following points. First, the lattice parameters and intra-plane first-neighbor bond lengths highly depend on the magnetic structures. Second, at x ≤ 0.25, the in-plane noncollinear antiferromagnetic (AFM) phase is most stable. Third, at x = 0.50, magnetic structures such as the out-of-plane spin canting structure, which are like superpositions of the AFM and ferromagnetic phases, are stable, and the magnetization easy axis is the c-axis. Finally, at x ≥ 1.00, the in-plane ferromagnetic phase is most stable, indicating that the easy axis is in the ab-plane, and the magnetocrystalline anisotropy energy reaches −1.60 MJ m−3 at x = 3.00.