BUSCADOR RECOLECTA

The influence of the atomic order on the martensitic transformation entropy change has been studied in a Ni-Mn-In-Co metamagnetic shape memory alloy through the evolution of the transformation temperatures under high-temperature quenching and post-quench annealing thermal treatments. It is confirmed that the entropy change evolves as a consequence of the variations on the degree of L21 atomic order brought by thermal treatments, though, contrary to what occurs in ternary Ni-Mn-In, post-quench aging appears to be the most effective way to modify the transformation entropy in Ni-Mn-In-Co. It is also shown that any entropy change value between around 40 and 5 J/kgK can be achieved in a controllable way for a single alloy under the appropriate aging treatment, thus bringing out the possibility of properly tune the magnetocaloric effect., This work has been carried out with the financial support of the Spanish “Ministerio de Economía y Competitividad” (projects number MAT2011-28217 C02-01 and MAT2012-37923 C02-01). The Institute Laue Langevin-Spanish CRG D1B installation is acknowledged for the allocated neutron beamtime (Exp. CRG 1905).