Barocaloric effects arise in materials when changes in applied pressure produce thermal changes. Giant barocaloric effects have therefore been suggested for cooling applications, but they are only seen in a small range of expensive magnetic materials. The present paper reports the discovery of superlative barocaloric effects in ferrielectric salts made of cheap abundant elements. The work should lead to the discovery of giant barocaloric effects in a wide range of unexplored inexpensive ferroelectric materials, and ultimately to efficient cooling devices.

Figure:  Refrigerant capacity of giant barocaloric materials at different values of applied pressure change |Δp|.