Multicaloric effect in ferroelectric PbTiO3 from first principles

The critical need in novel or alternative approaches to energy production, conversion, and harvesting, combined with the ongoing pursuit of device miniaturization, have revived interest in the long-known but "doomed" impractical caloric effects in solids. Contrary to the old belief that such effects, while common, are miniscule, a large variety of giant caloric effects has been recently discovered in some ferroic materials. These discoveries have opened the door to the use of these giant effects in an efficient and environmentally friendly solid-state refrigeration technology. Here we report first-principles simulations of multiple caloric effects in a typical ferroelastic ferroelectric PbTiO3 which offer insight into a multicaloric nature of this material. We predict the existence of unusual multicaloric effect in such electrically driven ferroelastic (extrinsic multiferroic) which far exceeds either electrocaloric or elastocaloric effect alone. Moreover, given a relative abundance of extrinsic multiferroics among ferroics with multiple order parameters, such prediction may open an unusual route to solid-state refrigeration advancement.