Theoretical prediction of ferrimagnetism in Mn2FeB, Mn2CoB and Mn2NiB

The electronic band structure and magnetic properties of Mn2FeB, Mn2CoB and Mn2NiB Heusler alloys are examined using the full-potential non-orthogonal local-orbital basis method (FPLO). Results of the calculations predict that the Hg2CuTi crystal structure is more stable than the L21 structure and the ground state of these alloys is ferrimagnetic. Both, the theoretical lattice parameter and the magnetic moment on Mn in site A increase with the replacement of Fe by Co atom and then by Ni atom. Band structure of Mn2FeB and Mn2CoB shows half-metallic features in some high-symmetry directions in the Brillouin zone. The highest spin-polarization at Fermi energy (88%) is expected for Mn2FeB.