NiMn-Based Metamagnetic Shape Memory Alloys

摘要

The magnetic properties of the parent and martensite phases of the Ni_2Mn_(1+x)Sn_(1-x) and Ni_2Mn_(1+x)In_(1-x) ternary alloys and the magnetic field-induced shape memory effect obtained in NiCoMnIn alloys are reviewed, and our recent work on powder metallurgy performed for NiCoMnSn alloys is also introduced. The concentration dependence of the total magnetic moment for the parent phase in the NiMnSn alloys is very different from that in the NiMnln alloys, and the magnetic properties of the martensite phase with low magnetization in both NiMnSn and NiMnln alloys has been confirmed by Moessbauer examination as being paramagnetic, but not antiferromagnetic. The ductility of NiCoMnSn alloys is drastically improved by powder metallurgy using the spark plasma sintering technique, and a certain degree of metamagnetic shape memory effect has been confirmed.