Stabilization of ferromagnetism and high spin polarization ratio in Cr-doped Fe2VSi

Abstract

Effect of Cr doping on the magnetic structure and electronic properties of Fe2VSi has been investigated by experimental measurement and first-principles calculations. In Fe2V1-xCrxSi, ferromagnetism can be stabilized with 10% Cr substitution. The Curie temperature TC increases rapidly with increasing Cr content and reaches 365K when x = 0.4. The saturation magnetization Ms also increases with increasing Cr content. A small amount of A15 secondary phase is observed with increasing Cr content at x = 0.4, indicating that the solid solubility of Cr in Fe2VSi has been reached. In Fe2V1-xCrxSi, high spin polarization ratio is predicted when x ≥ 0.25, and half-metallic character is observed when x = 0.5, 0.75 and 1.0. The calculated total spin moment Mt also increases with increasing x. When x is larger than 0.2/0.25, the experimental/theoretical total moment gets close to the Slater-Pauling curve of M = Z - 24 for half-metallic Heusler alloys. All this makes Fe2V1-xCrxSi promising candidates for spintronic applications.