Structure, magnetic properties and coercivity mechanism of rapidly quenched MnxGa ribbons

Recently, due to the short supply of rare earth element, there is a great demand in developing the rare-earth-free permanent magnets with giant magnetic anisotropy. Among the rare-earth-free permanent magnetic materials of current interest, Mn_xGa alloys are potential candidates as permanent magnets. In the Mn_xGa alloys, the ferromagnetic L1₀-MnGa phase and ferrimagnetic D0₂₂-Mn₃Ga phase are theoretically expected to have maximum energy product comparable with the commercial AlNiCo and ferrite permanent magnets. The two phases also show high spin polarization and low damping constant for application in spintronic devices and have been investigated intensively in the past decades. In our recent studies, the annealing time of the rapidly quenched Mn_xGa ribbons was reduced to 1 hour. In this study, the coercivity mechanism and exchange interaction in Mn_xGa alloy has been investigated.