Possible martensitic transformation and ferrimagnetic properties in Heusler alloy Mn sub(2)NiSn

The electronic structure and magnetic properties of Hg sub(2)CuTi-type Mn sub(2)NiSn have been studied by performing the first-principle calculations. It is found that the phase transformation from the cubic to the tetragonal structure reduces the total energy, indicating that the martensitic phase is more stable and the phase transition from austenite to martensite may happen at low temperature for Hg sub(2)CuTi-type Mn sub(2)NiSn. Concerning the magnetism of Hg sub(2)CuTi-type Mn sub(2)NiSn, both austenitic and martensitic phases are suggested to be ferrimagnets. Furthermore, martensitic transformation decreases the magnetic moment per formula unit compared with austenitic phase. The results are helpful to accelerate the use of Mn sub(2)NiSn alloys in the series for magnetic shape memory applications.