Giant reversible barocaloric effect with low hysteresis in antiperovskite PdNMn3 compound

Barocaloric (BC) refrigeration is a new type of clean and energy-efficiency refrigeration technology. However, the giant and colossal BC effects are mainly based on the first-order phase transitions, leading to the unfavorable hysteresis. Here we report the giant BC effect along with weak hysteresis at the antiferromagnetic (AFM) to paramagnetic (PM) phase transition (T-N = 283 K) in antiperovskite PdNMn3 compound. The reversible isothermal entropy change reaches 28.3 J kg(-1) K-1 under 290 MPa. The hysteresis is only about 2 K, which is associated with a small volumetric change Delta V/V at T-N (similar to 0.2%). The magnetic entropy is proposed to mainly contribute to the entropy change at T-N, which compensates for the reduced lattice contribution due to the small Delta V/V. Our result demonstrates the possibility of realizing giant BC effect together with weak hysteresis in materials where both crystallographic and non-crystallographic entropy changes cooperate at the first-order phase transition (FOPT). (C) 2021 Published by Elsevier Ltd on behalf of Acta Materialia Inc.

Automated summary

Barocaloric refrigeration is a new clean and energy-efficient technology, primarily based on first-order phase transitions which can lead to unfavorable hysteresis. This study demonstrates the potential for achieving a giant BC effect with weak hysteresis in the antiperovskite compound PdNMn3 during the AFM to PM phase transition.