Table-like shape magnetocaloric effect and large refrigerant capacity in dual-phase HoNi/HoNi2 composite**Project supported by the National Natural Science Foundation of China (Grant No. 51690162), Science and Technology Committee of Shanghai, China (Grant No. 19ZR1418300), Independent Research and Development Project of State Key Laboratory of Advanced Special Steel, Shanghai Key Laboratory of Advanced Ferrometallurgy, Shanghai University (Grant No. SKLASS 2019-Z003), and

Abstract

Nowadays, magnetic cooling (MC) technology by using the magnetocaloric effect (MCE) has attracted extensive research interest for its promising practical applications. A constant large/giant MCE covers wide refrigeration temperatures (denote as table-like shape) is beneficial for obtaining high efficiency performance for MC. In this paper, the HoNi/HoNi2 composite was successfully synthesized by arc-melting method and proved to be composed of HoNi and HoNi2 crystalline phases with weight ratios of 52.4 wt.% and 47.6 wt.%, respectively. The maximum magnetic entropy change () is 18.23 J/(kg⋅K), and the refrigerant capacity values RC1, RC2, and RC3 are 867.9 J/kg, 676.4 J/kg, and 467.8 J/kg with ΔH = 0–70 kOe, respectively. The table-like shape MCE and large refrigerant capacity values make the composite attractive for cryogenic MC using the Ericsson cycle.