Electronic structure and magnetism of Ti2FeSi: A first-principles study

• A half-metallic character is obtained for Ti2FeSi alloy, and thus potential use in spintronic devices.
• The sensitivity of magnetism with the change of the lattice constant is demonstrated.
• The evolution of the gap width in spin-down channel is determined as the lattice constant varies.

Electronic structure and magnetic calculations properties of the Ti-based Heusler alloys Ti2FeSi have been studied using the first-principles projector augmented wave potential within the generalized gradient approximation taking into account the Coulomb interaction. Calculated the density of states are discussed in terms of the contribution of Ti 3d24s2, Fe 3d64s2, and Si 3s23p2 partial density of states and the spin magnetic moments were also calculated. The density of states of the Ti2FeSi compound shows the spin-up electrons are metallic, but the spin-down electrons are semiconductor with a gap of 0.612 eV. Si atom shows only a small magnetic moment, but the magnetic moment of Fe atom is antiparallel to that of Ti atoms. The Ti2FeSi Heusler compound has a magnetic moment of 2 μB at the equilibrium lattice constant a=6.057 Å.