Computational screening of Fe-Ta hard magnetic phases

Abstract

In this paper, we perform a systematic calculation of the Fe-Ta phase diagram to discover hard magnetic phases. By using structure prediction methods based on evolutionary algorithms, we identify two energetically stable magnetic structures: a tetragonal Fe3Ta (space group 122) and a cubic Fe5Ta (space group 216) binary phase. The tetragonal structure is estimated to have both high saturation magnetization (mu M-0(s) = 1.14 T) and magnetocrystalline anisotropy (K-1 = 2.17 MJ/m(3)) suitable for permanent magnet applications. The high-throughput screening of magnetocrystalline anisotropy also reveals two low-energy metastable hard magnetic phases: Fe5Ta2 (space group 156) and Fe6Ta (space group 194), that may exhibit intrinsic magnetic properties comparable to SmCo5 and Nd2Fe14B, respectively.