Mn2YGa (Y=Ir and Pt), a promising shape memory alloy by DFT methods

Manganese-rich Heusler compounds attract much interest in the context of spin transfer torque, spin Hall Effect and rare earth free hard magnets. The Mn2Heusler compounds crystallize in the inverse cubic and tetragonal structure and are typified by antiparallel coupling of the magnetic moments on the Mn atoms. We give a comprehensive overview of the electronic and magnetic properties of both the cubic and tetragonal phases for Mn2-based Heusler materials, i.e., (Mn2IrGa and Mn2PtGa) in the ferromagnetic and antiferromagnetic ordering. Our calculation predicts that both the compounds have an inverse cubic structure in their ground states. Application of tetragonal distortion reduces the energy with respect to the cubic phase for both the materials. The equilibrium volumes of both the phases are nearly the same. The Curie temperatures and the magnetic moments of both the materials in both the cubic as well as tetragonal phases have been calculated. We find that the two materials have a high value of magnetocrystalline anisotropy for the tetragonal structure with low magnetic moments, which shows that these materials are promising candidates for spin-transfer-torque magnetization-switching applications.