Combining the magnetocaloric effect and barocaloric effect in low-cost Mn0.43−xNi0.77+xFe0.8Si intermetallics with broad refrigeration temperature region

Abstract

Solid-state refrigeration utilizing the caloric effects has been envisioned as an effective and environmentally friendly technology. In this work, we report low-cost Mn0.43−xNi0.77+xFe0.8Si (x = 0, 0.02, 0.04) intermetallics that exhibit tunable large magnetocaloric and barocaloric effects near room temperature. By increasing the Ni/Mn ratio (x = 0–0.04), the stable magneto-structural transitions from paramagnetic hexagonal to ferromagnetic orthorhombic phases can be established. The Mn0.41Ni0.79Fe0.8Si shows a maximum magnetic entropy change of about 18.2 J kg−1 K−1 under ΔH = 5 T and a maximum pressure-induced entropy change of about 39.4 J kg−1 K−1 under ΔP = 7.5 kbar. Through combining magnetocaloric and barocaloric effects, the refrigeration temperature region of Mn0.41Ni0.79Fe0.8Si can be broadened from 300 to 210 K, reaching ΔT = 90 K. Our findings provide a selectable approach to expand the refrigeration temperature region of solid-state refrigeration in MM′X intermetallics.