Large room temperature adiabatic temperature variation in a Ni40Co8Mn42Sn10 polycrystalline alloy

Abstract

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 ΔSM of 21.6 J kg−1K−1 and effective refrigeration capacity RCeff of 293 J kg−1 were achieved. Moreover, a large ΔTad up to −4.4 K was obtained under the low-field change of 1.5 T, which is much higher than previously reported ΔTad values in Ni-Mn-Sn based alloys.