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

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 enormouschallenge to mankind. Novel, efficient, and environmentally friendly refrigeration technologies based on solid-state refrigerants can offer away out of the problems arising from climate-damaging substances used in conventional vapor-compressors. Multicaloric materials standout because of their large temperature changes, which can be induced by the application of different external stimuli such as a magnetic, elec-tric, or a mechanical field. Despite the high potential for applications and the interesting physics of this group of materials, few studies focuson their investigation by direct methods. In this paper, we report on the advanced characterization of all relevant physical quantities thatdetermine the multicaloric effect of a Ni-Mn-In Heusler compound. We have used a purpose-designed calorimeter to determine the isother-mal entropy and adiabatic temperature changes resulting from the combined action of magnetic field and uniaxial stress on this metamag-netic shape-memory alloy. From these results, we can conclude that the multicaloric response of this alloy by appropriate changes of uniaxialstress and magnetic field largely outperforms the caloric response of the alloy when subjected to only a single stimulus. We anticipate thatour findings can be applied to other multicaloric materials, thus inspiring the development of refrigeration devices based on the multicaloriceffect.