Some aspects of strain-induced change of magnetization in a Ni-Mn-Ga single crystal

The strain-induced change in magnetization in a Ni50.3Mn28.7Ga21 single crystal is studied in an orthogonal magnetic field under cyclic deformation. Effect of the presence of magnetic field during martensitic transformation on both the mechanical and the magnetic behavior of the martensitic sample is examined. The following distinct aspects were observed: (1) change of magnetization (ΔM) is reversible and shows small hysteresis; (2) ΔM saturates after the strain reaches a certain level; and (3) both the reversible strain and magnitude of ΔM are increased if the sample has undergone martensite transformation under a magnetic field. The related mechanisms are proposed.