Flexocaloric Effect in a Cu-Al-Ni Single Crystal

Abstract Caloric effects are reversible thermal changes that occur in a solid material in response to an external field, either magnetic, electric or mechanical. Materials with large caloric effects are candidates to be used for environmentally friendly, solid-state refrigerators. In the case of mechanocaloric effect, thermal changes are induced by a mechanical field. Most of the work to date has been carried out by the application and removal of uniaxial stress or hydrostatic pressure and the corresponding caloric effects are usually denoted as elastocaloric and barocaloric effects, respectively. Mechanocaloric effects are very large when they occur associated with a ferroelastic phase transition involving a collective atomic rearrangement as occurs in martensitic phase transitions that involve a change of symmetry of the unit cell. Recently, it has been theoretically suggested that the possibility of actuating with more complex mechanical fields such as bending or twisting should have a several advantages. In this work we present a study of flexocaloric effect in superelastic materials exhibiting structural transitions.