Ultrasensitive barocaloric material for room-temperature solid-state refrigeration.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 35484158.
- Also identified by DOI 10.1038/s41467-022-29997-9 and PMC identifier 9051211.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
One of the greatest obstacles to the real application of solid-state refrigeration is the huge driving fields. Here, we report a giant barocaloric effect in inorganic NH<sub>4</sub>I with reversible entropy changes of [Formula: see text] ∼71 J K<sup>-1</sup> kg<sup>-1</sup> around room temperature, associated with a structural phase transition. The phase transition temperature, T<sub>t</sub>, varies dramatically with pressure at a rate of dT<sub>t</sub>/dP ∼0.79 K MPa<sup>-1</sup>, which leads to a very small saturation driving pressure of ΔP ∼40 MPa, an extremely large barocaloric strength of [Formula: see text] ∼1.78 J K<sup>-1</sup> kg<sup>-1</sup> MPa<sup>-1</sup>, as well as a broad temperature span of ∼41 K under 80 MPa. Comprehensive characterizations of the crystal structures and atomic dynamics by neutron scattering reveal that a strong reorientation-vibration coupling is responsible for the large pressure sensitivity of T<sub>t</sub>. This work is expected to advance the practical application of barocaloric refrigeration.