Influence of γ′ nanometric particles on martensitic transformation and twinning structure of L10 martensite in Co-Ni-Ga ferromagnetic shape memory single crystals

► Dense dispersions of nanometric particles generated in Co-Ni-Ga shape memory alloys. ► A very strong influence on the martensitic transformation is demonstrated. ► Precipitates do not change the martensite twinning mode. ► The unit cell tetragonality (c/a ratio) is clearly modified by the precipitates. ► This is attributed to the high symmetry of the martensite structure (tetragonal).