Electronic structure and half-metallicity in Heusler alloys Fe2YB (Y=Ti, V, Mn, Cr)

The electronic structure and magnetic properties of B-based Heusler alloys Fe2YB (Y=Ti, V, Cr and Mn) have been studied theoretically. These alloys are all ferrimagnets except for Fe2VB. The latter has 24 valence electrons and is a paramagnetic semimetal. Fe2CrB is predicted to be half-metals at equilibrium lattice constant. The spin polarization of Fe2MnB is also quite high. The calculated total moments are 1.00 μB for Fe2CrB and 2.04 μB for Fe2MnB. In Fe2CrB and Fe2MnB, the total moments are mainly determined by the partial moment of Cr or Mn. The Fe moment is relatively small and antiparallel to that of Cr or Mn. Under uniform lattice distortion, the half-metallicity of Fe2CrB is more stable than Fe2MnB, which is related to the detailed DOS structure of them near EF.