Epitaxial growth of hard ferrimagnetic Mn3Ge film on rhodium buffer layer

Abstract

Mn3Ge has a tetragonal Heusler-like D022 crystal structure, exhibiting a large uniaxial magnetic anisotropy and small saturation magnetization due to its ferrimagnetic spin structure; thus, it is a hard ferrimagnet. In this report, epitaxial growth of a Mn3Ge film on a Rh buffer layer was investigated for comparison with that of a film on a Cr buffer layer in terms of the lattice mismatch between Mn3Ge and the buffer layer. The film grown on Rh had much better crystalline quality than that grown on Cr, which can be attributed to the small lattice mismatch. Epitaxial films of Mn3Ge on Rh show somewhat small coercivity (Hc = 12.6 kOe) and a large perpendicular magnetic anisotropy (Ku = 11.6 Merg/cm3), comparable to that of the film grown on Cr.