Large barocaloric and magnetocaloric effects in MnFe0.8+xNi1.2−xSiGe0.5 high-entropy intermetallics

Abstract

High-entropy intermetallics (HEIs) are a category of materials that exhibit special functional properties. Among the many excellent properties of high-entropy materials, the magnetocaloric performance has a promising future. We design of HEIs of MnFe0.8+xNi1.2−xSiGe0.5 (x = 0, 0.2, 0.3, and 0.4) based on the MnNiSi. The change of Fe content establishes a stable magnetic structure transition from paramagnetic hexagonal phase to ferromagnetic orthorhombic phase, and a large magnetic entropy change of 25.8 and 32.8 J·kg−1 K−1 is obtained in x = 0.2 and 0.3 materials under the field of 3 T. Moreover, the transition temperature of the MnFeNiSiGe0.5 HEI decreases with increasing pressure, and a low-pressure-induced large reversible barocaloric effect is achieved with the transformation entropy change of 43.72 J·kg−1 K−1 by applying hydrostatic pressure of 10 kbar. Our findings demonstrate that MnFe0.8+xNi1.2−xSiGe0.5 HEIs have promising potential as high-performance solid state refrigeration materials.