Magnetic entropy changes of NiMnGa alloys both on the heating and cooling processes

Magnetic entropy changes of Ni53.6Mn23.2Ga23.2 and Ni54.7Mn20.2Ga25.1 alloys on the heating and cooling processes were studied in this article. The magnetic entropy change (ΔSH) is negative on the heating process. While the magnetic entropy change (ΔSC) is positive on the cooling process. For Ni53.6Mn23.2Ga23.2, the difference between the peak values of ΔSH and ΔSC is small under the field change of 2 T. But for Ni54.7Mn20.2Ga25.1, the difference between the peak values of ΔSH and ΔSC is large under the field change of 2 T.