Structure stability and magnetic properties of Fe-doped Co2VGa Heusler alloys: Insights from first-principles calculations

Abstract

In this work, we report an interesting phenomenon with respect to the coexistence of martensite phase transformation (MPT) and half-metallic properties in Fe doped Co2VGa Heusler alloys, which is predicted theoretically according to the ab initial calculations based on density functional theory (DFT). The effects of Fe partial substitution for Co, V or Ga atoms on the structural stability, MPT, electronic structure and magnetic properties in Co-V-Ga system alloys have been systematically investigated. It was found that Co2-xFexVGa (x = 0, 0.25, 0.5, 0.75, 1), Co2V0.75Fe0.25Ga and Co2VFe0.25Ga0.75 alloys are stable in highly ordered L21-type structure. The magnetic analysis indicates that the magnetic moment decreases with the increase of Fe content in Co2-xFexVGa (x = 0, 0.25, 0.5, 0.75, 1) alloys, whereas it increases with the increase of Fe content for V or Ga partially replaced by Fe atoms. According to the calculated results, MPT can take place in Co2V0.5Fe0.5Ga and Co2VFe0.5Ga0.5 Heusler alloys. All the studied alloys exhibit high spin polarizability, especially in the alloys of Co or V partially replaced with Fe.