Large room temperature adiabatic temperature variation in a Ni40Co8Mn42Sn10 polycrystalline alloy

For the potential applications in magnetic refrigeration, low-cost and high-performance refrigerants with large magnetocaloric effect at relatively lower field change are highly desired. In this work, we report a large adiabatic temperature variation for a low-field change of 1.5 T near room temperature in a Ni40Co8Mn42Sn10 bulk alloy. With the large magnetization difference between weak magnetic martensite and ferromagnetic austenite, this alloy exhibits significant inverse magnetocaloric effect. Under the field change of 5 T, large magnetic entropy change Delta S-M of 21.6 J kg(-1) K-1 and effective refrigeration capacity RCeff of 293 J kg(-1) were achieved. Moreover, a large Delta T-ad up to - 4.4 K was obtained under the low-field change of 1.5 T, which is much higher than previously reported Delta T-ad values in Ni-Mn-Sn based alloys.