Multicaloric effects in Metamagnetic Heusler Ni-Mn-In under uniaxial stress and magnetic field

TL;DR

This study investigates the multicaloric effect in Ni-Mn-In Heusler alloys under combined magnetic and uniaxial stress stimuli, demonstrating enhanced temperature changes for potential solid-state refrigeration applications.

Contribution

It provides the first advanced characterization of the multicaloric response in Ni-Mn-In Heusler alloys using a custom calorimeter, highlighting the superior effect of combined stimuli.

Findings

Multicaloric response exceeds single-stimulus effects.

Combined magnetic and stress stimuli induce larger temperature changes.

Results suggest potential for environmentally friendly refrigeration technologies.

Abstract

The world's growing hunger for artificial cold on the one hand, and the ever more stringent climate targets on the other, pose an enormous challenge to mankind. Novel, efficient and environmentally friendly refrigeration technologies based on solid-state refrigerants can offer a way out of the problems arising from climate-damaging substances used in conventional vapor-compressors. Multicaloric materials stand out because of their large temperature changes which can be induced by the application of different external stimuli such as a magnetic, electric, or a mechanical field. Despite the high potential for applications and the interesting physics of this group of materials, only few studies focus on their investigation by direct methods. In this paper, we report on the advanced characterization of all relevant physical quantities that determine the multicaloric effect of a Ni-Mn-In Heusler compound. We have used a purpose-designed calorimeter to determine the isothermal entropy and adiabatic temperature changes resulting from the combined action of magnetic field and uniaxial stress on this metamagnetic shape-memory alloy. From these results, we can conclude that the multicaloric response of this alloy by appropriate changes of uniaxial stress and magnetic field largely outperforms the caloric response of the alloy when subjected to only a single stimulus. We anticipate that our findings can be applied to other multicaloric materials, thus inspiring the development of refrigeration devices based on the multicaloric effect.