Fe2MnSn Heusler alloy based rare-earth-free permanent magnets

Considering the vast compositional space of Heusler alloys, first-principles-based calculations are ideally suitable for predicting the ground state structure and tailoring the magnetic properties of these alloys. We perform density-functional-theory-based calculations for step-by-step identification of the most stable phase of Fe2MnSn, followed by the calculations of magnetic properties. Ferromagnetic hexagonal phase is identified to be the stable structural phase of Fe2MnSn with a large magnetization (6.45 mu B/f.u.), high Curie temperature (729 K) but with an in-plane magnetic anisotropy. On doping with light interstitial atoms (B, C, H, N and O) an out-of-plane anisotropy can be engineered with enhanced magnetic properties, making this material suitable for permanent magnet applications.