Significant low-temperature conventional and inverse magnetocaloric effects in ErSb and HoSb compounds

Abstract

The low-temperature magnetocaloric (MC) effects in many rare-earth (RE)-dominated solid-state magnets were extensively studied in recent years to develop high-performance MC materials for magnetic cooling application and deepen clarifying their underlying magnetic characters. We herein synthesized two single-phased RE-dominated magnetic solids, namely the ErSb and HoSb compounds, by the induction-melting method and experimentally unveiled their structural and magnetic properties, specifically their magnetic phase transition and low-temperature MC properties. Both compounds crystallize in the NaCl-type cubic structure (Fm-3m space group) with a uniform microstructure and exhibit low-temperature antiferromagnetic (AFM) ordering at approximately 3.7 K and 5.5 K for the ErSb and HoSb compounds, respectively. Meanwhile, they exhibit significant low-temperature conventional and inverse low-temperature MC effects, attributed to their AFM ground state and unique, first-order field-induced magnetic phase transition (MPT). Moreover, we identified their conventional MC performance using the magnetic entropy change/temperature-averaged entropy change (5 K-lift) and refrigerant capacity, which are 20.8/19.2 J/kg·K and 214.3 J/kg for ErSb, and 22.3/21.5 J/kg·K and 256.6 J/kg for HoSb, respectively. These MC parameters of ErSb and HoSb are comparable to most known high-performance low-temperature RE-dominated MC materials, making them attractive candidates for practical cooling application.