Half-metallicity and magnetic properties of half-Heusler type Mn ₂Sn: Ab initio predictions

Ab initio calculations have been carried out to investigate the electronic structure and magnetism of the compound Mn₂Sn with the bcc half-Heusler structure. For the equilibrium lattice parameter 5.69 A, Mn ₂Sn is predicted to be a half-metallic fully compensated ferrimagnet (also called half-metallic antiferromagnet) with zero total spin moment. This zero moment agrees well with the Slater-Pauling curve and mainly comes from the compensated Mn (A) and Mn (B) spin moments in antiparallel configuration. The half-metallicity of Mn₂Sn is stable in a wide lattice-parameter range from 5.6 A to 5.9 A. Upon contraction of the lattice, a transition from half-metallicity to semimetallicity is observed.