Table-like shape magnetocaloric effect and large refrigerant capacity in dual-phase HoNi/HoNi₂ composite

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 ( -\rm\Delta S_M^\rm\max ) 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.