Electronic structure and magnetic property of MnSn: Prediction of half-metallic ferromagnetism in zinc-blende structure

The electronic and magnetic properties of the transition-metal compound MnSn were studied, using the full potential augmented plane wave plus local orbitals method within density functional theory. The total energy calculations show, amongst four investigated structures: zinc-blende, NaCl, CsCl, and NiAs, MnSn prefers the antiferromagnetic NiAs structure at the ground state. It was found that only the zinc-blende metastable phase is a half-metallic ferromagnet with a magnetic moment of 3.00μB per formula unit, the ferromagnetic configuration is more stable than the antiferromagnetic one energetically. Its half-metallic gap reaches 0.24 eV at the equilibrium volume, and keep non-zero until compressed by 16% in the relative volume. The details of the electronic structure of zinc-blende MnSn were examined, the half-metallicity is attributed to the large exchange splitting and bonding-antibonding splitting. The volume compression results in the upward movement of the Fermi level, due to the increase in bandwidths, under the volume expansion an opposite behavior was found.