Colossal barocaloric effects near room temperature in plastic crystals of neopentylglycol

There is currently great interest in replacing the harmful volatile hydrofluorocarbon fluids used in refrigeration and air-conditioning with solid materials that display magnetocaloric, electrocaloric or mechanocaloric effects. However, the field-driven thermal changes in all of these caloric materials fall short with respect to their fluid counterparts. Here we show that plastic crystals of neopentylglycol (CH 3 ) 2 C(CH 2 OH) 2 display extremely large pressure-driven thermal changes near room temperature due to molecular reconfiguration, that these changes outperform those observed in any type of caloric material, and that these changes are comparable with those exploited commercially in hydrofluorocarbons. Our discovery of colossal barocaloric effects in a plastic crystal should bring barocaloric materials to the forefront of research and development in order to achieve safe environmentally friendly cooling without compromising performance. There is great interest, in refrigeration technology, in replacing harmful volatile hydrofluorocarbons with solid materials. Here the authors show that commercially available plastic crystal neopentylglycol displays colossal and reversible barocaloric effects comparable with those exploited in hydrofluorocarbons, which make it suitable for application.