Barocaloric Effect in Oxyfluorides Rb2KTiOF5 and (NH4)2NbOF5

Abstract

Using the data about the temperature–pressure phase diagram and the phase transition entropy at ambient pressure, intensive ΔT AD and extensive ΔS BCE barocaloric effects were estimated near structural order-disorder phase transitions in oxyfluorides Rb2KTiOF5 and (NH4)2NbOF5. It was found that hydrostatic pressure is an effective tool to change the entropy of compounds with ordering ionic groups in structure and to realize the significant caloric effects comparable with the values of electro- and magnetocaloric effects, characteristic for a number of materials, considered as promising solid refrigerants.