Understanding Entropy Changes in Layered Barocaloric Materials

Large entropy changes in barocaloric materials can be leveraged to drive high-efficiency, solid-state cooling cycles. To develop a greater molecular-level understanding of entropy changes in barocaloric materials, Mason measured temperature-dependent molecular dynamics in barocaloric salts and perovskites using neutron scattering. Kozinsky used molecular dynamics (MD) simulations to identify specific molecular geometries and amplitudes of motion that correlate to the experimental results. They showed that a combination of a more restricted ordered phase and more flexible disordered phase resulted in a larger entropy change for a barocaloric salt material. These molecular-level insights enable their team to rationally design barocaloric materials as higher-performing solid refrigerants.