Large Magnetic Entropy Change and Magnetic-Controlled Shape Memory Effect in Single Crystal Ni46Mn35Ga19

Abstract:

Physical properties of Ni46Mn35Ga19 single crystal with transition temperatures above room temperature were investigated by various measuring methods. The measuring results of the resistance and ac susceptibility indicate that the magnetic transition and martensitic transformation can occur simultaneously in this alloy. The measurements of the isothermal magnetization show that the increasing rate of magnetic entropy change in this alloy is 9.0 J / kg·K·T. A large magnetic entropy change of 13.8 J/kg·K is obtained under the field of 1.6 T in the single crystal. Furthermore, the strain measurement shows that accompanying with magnetic entropy change, the alloy exhibits a large spontaneous transition strain of –0.89% and a large magnetic-field-enhanced strain of –1.90%.

Key words:shape memory effect; magnetic entropy change; magnetic transition; martensitic transformation