R. Kainuma, W. Ito, K. Oikawa, K. Ishida, Tohoku University, Sendai, Japan
Recently, we have found that some Ni-Mn based alloys with a Heusler-type structure, such as Ni-Mn-In and Ni-Mn-Sn, show a unique transformation from ferromagnetic parent (P) to antiferromagnetic-like martensite (M) phase and that a meta-magnetic phase transition from the M to P phase is induced by a magnetic field. Furthermore, a shape memory effect due to the magnetic-field induced reverse transformation, namely, meta-magnetic shape memory effect, can be obtained in NiCoMnIn and NiCoMnSn alloys. In this paper, magnetic and martensitic properties of these alloys will be reviewed and the details of the meta-magnetic shape memory effect will be presented.
