Insights into Fe doping-induced modifications in martensitic transformation, magnetic properties, and mechanical performance of Co–V–Ga alloys

This work systematically explores the impact of Fe doping on the phase stability, martensitic transformation, and magnetic properties of Co50−xV37.5Ga12.5Fex alloys (where x = 3.125, 6.25, 9.375, 12.5, and 15.625) through first-principles calculations. The findings reveal a pronounced tendency of Fe atoms to cluster within the alloy. Increasing Fe content results in a progressive decline in lattice constants and phase stability for both austenite and martensite, primarily due to modifications in electronic bonding interactions. Additionally, Fe doping reduces the martensitic transformation temperature of the Co–V–Ga alloys. Co–V–Ga–Fe alloys exhibit a transformation from ferromagnetic austenite to weakly magnetic martensite across all studied compositions, suggesting promising applications in magnetic technologies. The plasticity of the Co–V–Ga alloy is substantially enhanced by Fe doping. The electronic structure perspective elucidates the physical mechanisms of martensitic transition, lattice constants, and magnetic change in alloys.