Colossal barocaloric effects in plastic crystals

TL;DR

This paper reports colossal barocaloric effects in plastic crystals, showing promise for solid-state refrigeration with high entropy changes driven by molecular disorder and lattice dynamics.

Contribution

It identifies and explains the microscopic origin of colossal barocaloric effects in plastic crystals, advancing solid-state cooling technology.

Findings

Entropy change of about 380 J kg-1 K-1 in neopentylglycol

CBCEs linked to molecular disorder and lattice anharmonicity

Potential for next-generation refrigeration technology

Abstract

Solid-state refrigeration technology based on caloric effects are promising to replace the currently used vapor compression cycles. However, their application is restricted due to limited performances of caloric materials. Here, we have identified colossal barocaloric effects (CBCEs) in a class of disordered solids called plastic crystals. The obtained entropy changes are about 380 J kg-1 K-1 in the representative neopentylglycol around room temperature. Inelastic neutron scattering reveals that the CBCEs in plastic crystals are attributed to the combination of the vast molecular orientational disorder, giant compressibility, and high anharmonic lattice dynamics. Our study establishes the microscopic scenario for CBCEs in plastic crystals and paves a new route to the next-generation solid-state refrigeration technology.