Atomistic calculations of elastocaloric effects in ferroelectric materials

Elastocaloric effects (i.e., the change in temperature due to the application or removal of a mechanical stress) in ferroelectric materials could provide us with an alternative to current – and very polluting – cooling technologies. Ferroelectric phase transitions – as, e.g., in prototype materials like PbTiO₃ – have an elastic transformation associated to them, which could potentially give rise to strong elastocaloric effects. Here we introduce a theoretical approach to compute and analyze the elastocaloric response from atomistic simulations and present our results for PbTiO₃. Our results reveal several unusual features (i.e., strong anisotropy of the elastocaloric response, the possibilty to choose its sign) that we discuss in detail.