Colossal barocaloric effects near room temperaturein plastic crystals of neopentylglycol

There is currently great interest in replacing the harmful volatile hydrofluorocarbonfluidsused in refrigeration and air-conditioning with solid materials that display magnetocaloric,electrocaloric or mechanocaloric effects. However, thefield-driven thermal changes in all ofthese caloric materials fall short with respect to theirfluid counterparts. Here we show thatplastic crystals of neopentylglycol (CH3)2C(CH2OH)2display extremely large pressure-driven thermal changes near room temperature due to molecular reconfiguration, that thesechanges outperform those observed in any type of caloric material, and that these changesare comparable with those exploited commercially in hydrofluorocarbons. Our discovery ofcolossal barocaloric effects in a plastic crystal should bring barocaloric materials to theforefront of research and development in order to achieve safe environmentally friendlycooling without compromising performance