Martensitic transformation in Cu-doped Ni-Fe-Ga rapidly quenched ribbon

Martensitic transformation (MT), structural and magnetic properties were investigated in a rapidly quenched Cu-doped Ni-Fe-Ga ribbon. The X-ray room temperature diffraction pattern showed the austenitic phase with the presence of the martensitic phase in the sample that was confirmed by SEM images. We have found that residual martensitic phase disappears at 320 K, while the MT and magnetic phase transition occurs above room temperature. Thermally stable two-step behavior of the MT, associated with the intermartensitic transition, has been shown. The MT affects static magnetic properties showing a small difference in magnetization values between curves measured during the heating and cooling. Results were discussed in the frame of the copper dopant and internal stresses, arising in the ribbon due to the fabrication features.