Investigation of martensitic transition and inverse magnetocaloric property in Ni-Mn-Sn Heusler alloys

Abstract

The martensitic transition and magnetocaloric property in Ni50Mn25+xSn25-x (x=11, 12) Heusler alloys were investigated by means of structure and magnetism measurements. The results show that the antiferromagnetic interaction strengthens in the martensitic state, leading to the coexistence of ferromagnetic and antiferromagnetic interaction in this state, which is different from the magnetic property of austenitic state in these alloys. Furthermore, based on Maxwell equation, the inverse magnetocaloric property near martensitic transition temperature of this system was studied. It was found that large positive magnetic entropy change (ΔSM) depends on both magnetic jumping (ΔM) and temperature region during martensitic transition.