Magnetocaloric effect in ferromagnetic Heusler shape-memory alloys

In this paper the magnetocaloric behaviour of Ni-Mn-based Heusler alloys is discussed in relation to their shape-memory and superelastic properties. We show that the magnetocaloric effect in these materials originates from two different contributions. The first, associated with the mechanism which makes feasible the magnetically induced rearrangement of martensite variants, controls the magnetocaloric effect at low applied fields, while the latter is dominant at higher fields and is essentially related to the possibility of magnetically inducing the martensitic transition. The occurrence of the inverse magnetocaloric effect associated with these two contributions is also considered.