Development of Ni-Mn-Ga Based Ferromagnetic Shape Memory Alloy by Rapid Solidification Technique
Rapid solidification route by melt spinning has been adopted for preparation of a Ni52.5Mn24.5Ga23 (at %) ferromagnetic shape memory alloy in the form of ribbons. In the as-spun state, the ribbon revealed a predominant austenitic L21 structure in combination with martensitic feature as observed from x-ray diffraction studies. Transmission electron microscopic (TEM) evaluation showed these features in the form of martensitic plates. At low temperature, martensite to austenite transformation was exhibited by an increase in magnetization during heating cycle. The reverse effect was observed during cooling cycle. Annealing temperature and magnetising field was also found to effect this transformation.
Lluis Mañosa, P.K. Mukhopadhyay and S.R. Barman
A. Mitra and A.K. Panda, "Development of Ni-Mn-Ga Based Ferromagnetic Shape Memory Alloy by Rapid Solidification Technique", Advanced Materials Research, Vol. 52, pp. 17-27, 2008