Site preference and electronic structure of Mn2RuSn: A theoretical study

• Hg2CuTi-type structure is energetically favored in Heusler alloy Mn2RuSn.
• Mn2RuSn becomes half-metallic with a small contraction of the lattice.
• A tetragonal martensitic transformation is predicted in Mn2RuSn.
• Mn2RuSn can be a potential candidate for spintronic applications like STT.

The site preference, electronic structure and magnetism of a newly discovered Heusler alloy Mn2RuSn have been investigated. The Hg2CuTi-type (XA) structure is found to be energetically favored in Mn2RuSn. Mn2RuSn is a normal ferrimagnetic metal at equilibrium lattice constant, but with 2% contraction of the lattice, it becomes a half-metal with a spin moment of 2μB. A tetragonal martensitic transformation is predicted in Mn2RuSn. The total moment of the tetragonal phase is near zero, which results in a large ΔM between the saturation moments of martensite and austenite. Finally, in tetragonal Mn2RuSn, a high spin polarization ratio of 93% is predicted. These properties make Mn2RuSn a potential candidate for spintronics materials.