We have investigated the crystallographic and magnetic properties of (Mn,Fe)3-δGa alloys. The hexagonal phase is stable between 600 and 700 °C and can be stabilized by quenching to room temperature. Mn3Ga is reported to be off-stoichiometric, but we show that using melt-spinning the stoichiometric compound is attainable. Below the antiferromagnetic transition temperature TN, the crystal undergoes a hexagonal to monoclinic transition at the distortion temperature Td. This gives rise to an in-plane rotation of the magnetic moments that is accompanied by a simultaneous increase in magnetization in a magnetic field of 1 T. Fe substitution for Mn removes the monoclinic distortion. Substitutional Fe weakens the antiferromagnetism and a paramagnetic to ferromagnetic transition is observed. The Mn sublattice couples antiparallel throughout the series. Substitution of Ga with Si preserves the monoclinic distortion.
- Antiferromagnetic spintronics
- Magnetoelastic transition
- Triangular antiferromagnet