91福利

Caloric effects in shape-memory alloys

Lluís Mañosa

Departament d’Estructura i Constituents de la Matèria

Facultat de Física. Universitat de Barcelona. Catalonia.

Caloric effects refer to the adiabatic temperature change or the isothermal entropy change taking place in any thermodynamic system on varying an external field. Although these effects are small in a majority of systems, they become enhanced in the vicinity of phase transitions and are particularly large at first-order phase transitions. The observation of giant caloric effects around room temperature has prompted research in this field motivated by the potential use of materials with such properties in efficient and environmentally friendly refrigeration devices. 

Shape-memory alloys undergo a martensitic transition. This is a first-order structural transition which involves significant entropy change. In my talk, I will show experimental evidences on how this transition can be induced by different external influences (stress, pressure and magnetic field) and give rise to a series of caloric effects; namely the elastocaloric, barocaloric and magnetocaloric effects.