The Role of Chemical Pressure in the Formation of the Structure and Barocaloric Properties of Complex Fluorides and Oxyfluorides

https://doi.org/10.1134/S1063774523600485

The role of chemical pressure as an effective tool in the processes of formation of initial and distorted (as a result of structural transformations) phases, thermodynamic properties, and direct and inverse barocaloric effects in some complex oxyfluorides and fluorides with octahedral, tetrahedral, and spherical anion and cation groups in the structure has been studied. It is found that, due to the small temperature hysteresis and high baric sensitivity of materials, the maximum values of absolute and integral barocaloric characteristics can be implemented at low pressures. Correspondingly, the temperature range of reversibility of thermodynamic cycles based on fluorides/oxyfluorides as solid-state coolants can be expanded.