Dynamic control and increase of working temperature range in Ni-Mn-In-Co MCE materials by hydrostatic pressure or biaxial stress

In order to achieve carbon neutrality, solid-state phase-change refrigeration technology based on magnetocaloric effects (MCE) is considered one of the most potential alternatives to traditional refrigeration technology. At this stage, the fixed and relatively narrow operating temperature window still remains a major disadvantage for future refrigeration applications. Hence, this work aims to show that working temperature in Ni-Mn-In-Co MCE materials can be dynamically tuned by hydrostatic pressure or biaxial stress. Our results show that Ni21Mn18In6Co3 presents adjustable operating temperature range (from 310 K to 328 K) under pressure (0-3 GPa). Unlike hydrostatic pressure, biaxial stress with compression or tension can achieve bidirectional control of martensitic transformation temperature, further widening the operating temperature range. The biaxial strain from - 1.5-1.5 % can tune the operating temperature range from 292 K to 344 K in Ni21Mn18In6Co3 alloys. Also, the physical mechanism of dynamic control and increase of working temperature range in Ni-Mn-In-Co using physical pressures is revealed detailly. Moreover, the results show that both hydrostatic pressure and biaxial stress do not decrease the curie temperature (TC), and improve the magnetization difference (Delta M) between austenite and NM martensite phases. It further proves that applying physical pressures can be an effective strategy with simultaneous enhancement of working temperatures and magnetic properties. Data availability: The data that supports the findings of this study are available within the article.