Large magnetic entropy change in Ni50 Mn50-x Inx Heusler alloys

The magnetocaloric properties of polycrystalline Ni50 Mn50-x Inx (15≤x≤16) associated with the second order magnetic transition at the Curie temperature and the first order martensitic transition were studied using magnetization measurements. The refrigeration capacity and magnetic entropy change were found to depend on the In concentration and reach a maximum value of refrigeration capacity of 280 Jkg with a magnetic entropy change of -6.8 Jkg K at 318 K for a magnetic field change of 5 T. These values of the magnetocaloric parameters are comparable to that of the largest values reported near the second order transition of metallic magnets near room temperature. © 2007 American Institute of Physics