Ultrahigh cyclability of a large elastocaloric effect in multiferroic phase-transforming materials

Multiferroic phase-transforming alloys demonstrate intriguing multicaloric effects, but they are intrinsically brittle and their elastocaloric effect shows poor cyclability, which remains a major challenge for exploiting more efficient multicaloric refrigeration. Here, by employing a novel strategy of strengthening grain boundary, the cyclability of elastocaloric effect in the prototype Ni-Mn-based multiferroic phase-transforming alloys is strikingly enhanced by two orders of magnitude. Ultrahigh cyclability of a large elastocaloric effect is achieved. This not only paves the way for exploiting multicaloric effects for more efficient cooling, but also provides a strategy for overcoming the cyclability issues in the ubiquitous brittle intermetallic phase-transforming materials.