A Colossal barocaloric effect induced by the creation of a high-pressure phase

Jiang, X.*; Hattori, Takanori   ; Xu, X.*; Li, M.*; Yu, C.*; Yu, D.*; Mole, R.*; Yano, Shinichiro*; Chen, J.*; He, L.*; Wang, C.-W.*; Wang, H.*; Li, B.*; Zhang, Z.*

As a promising environment-friendly alternative to current vapor-compression refrigeration, solid-state refrigeration based on the barocaloric effect has been attracting world wide attention. Generally, both phases in which a barocaloric effect occurs are present at ambient pressure. Here, instead, we demonstrate that KPF exhibits a colossal barocaloric effect due to the creation of a high-pressure rhombohedral phase. The phase diagram is constructed based on pressure-dependent calorimetric, Raman scattering, and neutron diffraction measurements. The present study is expected to provide an alternative routine to colossal barocaloric effects through the creation of a high-pressure phase.