Relaxation in Ni–Mn–Ga ferromagnetic shape memory alloys

Abstract Evidence of relaxation has been observed in ferromagnetic Ni–Mn–Ga single crystals. The relaxation may be explained by a change in symmetry-conforming short-range ordering according to Ren and Otsuka in this off-stoichimetric ordered alloy. Martensite stabilization has also been found after martensite ageing. Acknowledgements The author, X. Jin, gratefully appreciates the financial support received from Shanghai Jiao Tong University during his stay at Massachusetts Institute of Technology (MIT). The authors also wish to thank Ms Y. L. Xie and Mr J. K. Huang, MIT, for help with the sample treatments and measurements. The crystals used in our study were grown by Dr Tom Lograsso of Ames Laboratory (US Department of Energy).