Realization of giant elastocaloric cooling at cryogenic temperatures in TmVO$_4$ via a strain load/unload technique

TL;DR

This study demonstrates a giant elastocaloric cooling effect in TmVO$_4$ at cryogenic temperatures using a strain load/unload technique, highlighting its potential for low-temperature cooling applications.

Contribution

It introduces a strain load/unload method to achieve significant elastocaloric cooling in TmVO$_4$ at cryogenic temperatures, expanding the application scope of elastocaloric materials.

Findings

Achieved approximately 50% cooling of initial temperature at 5 K with 1.8×10^{-3} strain change.

Established TmVO$_4$ as a promising material for cryogenic elastocaloric cooling.

Provided insights into the entropy landscape near the quadrupolar phase transition.

Abstract

The adiabatic elastocaloric effect relates changes in the strain that a material experiences to resulting changes in its temperature. While elastocaloric materials have been utilized for cooling in room temperature applications, the use of such materials for cryogenic cooling remains relatively unexplored. Here, we use a strain load/unload technique at low temperatures, similar to those employed at room-temperature, to demonstrate a large cooling effect in TmVO$_4$. For strain changes of $1.8 \cdot 10^{-3}$, the inferred cooling reaches approximately 50% of the material's starting temperature at 5 K, justifying the moniker "giant". Beyond establishing the suitability of this class of material for cryogenic elastocaloric cooling, these measurements also provide additional insight to the entropy landscape in the material as a function of strain and temperature, including the behavior proximate to the quadrupolar phase transition.