Effect of pressure on the phase stability and magnetostructural transitions in nickel-rich NiFeGa ribbons

Ribbons of a Ni55Fe19Ga26 Heusler alloy were prepared by melt spinning technique. The effect of pressure on magnetostructural transitions was studied comparing as-spun ribbons to ribbons previously submitted to an axial pressure and to powder obtained from manually grinded as-spun ribbons. The martensitic transformation present in the as-spun ribbon almost vanishes after pulverization. The structural change driven by mechanical treatment is a stress-induced intermartensitic transformation from a 14 M modulated to a non-modulated tetragonal (NM) structure. There is a progressive change from the structure of as-spun samples to that of the pulverized one in samples submitted to axial pressures as it increases. •Effect of pressure in a Ni55Fe19Ga26 ribbon has been analyzed.•Mechanical treatment induces a transformation from a 14 M to a NM structure.•Martensite transition vanishes after pulverization.•14 M structure cannot be recovered by annealing once the ribbon is pulverized.•The formation of the γ phase can be an obstacle to this recovery.