Cooling is essential for food and drinks, medicine, electronics and thermal comfort. Thermal changes due to pressure-driven phase transitions in fluids have long been used in vapour-compression systems to achieve continuous refrigeration and air conditioning, but their energy efficiency is relatively low, and the working fluids that are employed harm the environment when released to the atmosphere. More recently, the discovery of large thermal changes due to pressure-driven phase transitions in magnetic solids has led to suggestions for environmentally friendly solid-state cooling applications. However, for this new cooling technology to succeed, it is still necessary to find suitable barocaloric materials that satisfy the demanding requirements set by applications, namely very large thermal changes in inexpensive materials that occur near room temperature in response to small applied pressures.
This action was aimed at developing new barocaloric materials by exploiting phase transitions in non-magnetic solids whose structural and thermal properties are strongly coupled. These materials are normally made from cheap abundant elements, and display very large latent heats and volume changes at structural phase transitions, which make them ideal candidates to exhibit extremely large barocaloric effects that outperform those observed in expensive barocaloric magnetic materials, and that match applications needs.
The outputs of the action include the development of colossal barocaloric effects in organic and hybrid organic-inorganic materials that display thermal changes on-par with commercial gas refrigerants, and the development of the first-ever barocaloric prototype.
