Temperature and field induced strain in polycrystalline Ni50Mn35In15−xSix magnetic shape memory Heusler alloys

Magnetic shape memory properties of polycrystalline Ni50Mn35In15−xSix were investigated. A reversible strain of more than 0.4% was observed for x = 0 at a magnetic field H = 5 T that was found to be associated with a field induced reverse martensitic transformation. The strains were found to increase with the substitution of In by Si and strains larger than 1% were observed for x = 2 at H = 5 T. Both the positive and negative strain changes were observed in the vicinity of martensitic transition temperatures. The strain in Ni50Mn35In15−xSix was found to depend on silicon concentration, and on samples texture.

Research highlights▶ A reversible shape memory effect with a strain as large as 0.4% was observed at room temperature at a magnetic field of 5 T for polycrystalline Ni50Mn35In15. ▶ The sign of the volume anomaly at martensitic transition (TM), and the magnitude of the strains were found to depend on sample textures. ▶ A significantly large strain with a maximum value of about ≈1% was found for Ni50Mn35In15−xSix at a magnetic field of H = 5 T (without applying the prestrain). This value is significantly higher than that recently reported for polycrystalline Ni–Mn–X (X = In, Sb, Sn).