Magnetic Properties of Boron-Doped Co $_{2}$ FeSi: A First-Principles Study

A new half-metallic Heusler alloy candidate boron-doped Co₂FeSi is predicted by first-principles calculations based on density functional theory. It is found that the lattice parameter of Co₂FeSi_1-xB_x decreases linearly with the increasing x. The magnetic moment shows a similar trend and is close to that of Co₂FeAl at the extreme component x = 1. The electronic structure studies indicate that with the increasing x, the Fermi level shifts from the bottom of conduction band to the top of valence band in the minority spin states. When B atoms substitute 50% of Si atoms, the Fermi level locates in the middle of the minority spin band gap, which suggests the structure to be an ideal half-metallic compound processing 100% spin polarization. According to the calculations, B-doped Co₂FeSi is a promising candidate for spintronic materials.