New hard magnetic phase in Mn-Ga-Al system alloys

We report a new hard magnetic phase in the Mn65Ga35−xAlx system. A Mn65Ga35 sample consisting of the D022-type Mn3Ga phase exhibited a coercivity of 400 kA/m. The partial replacement of Ga with Al in the Mn65Ga35 sample resulted in the formation of a new cubic phase with a Curie temperature of 680 K. This cubic phase exhibited a coercivity of 730 kA/m, which is higher than that of the D022-type Mn3Ga phase.