Large inverse and normal magnetocaloric effects in HoBi compound with nonhysteretic first-order phase transition

Abstract

HoBi single crystal and polycrystalline compounds with NaCl-type structure are successfully obtained, and their magnetic and magnetocaloric properties are studied in detail. With temperature increasing, HoBi compound undergoes two magnetic transitions at 3.7 K and 6 K, respectively. The transition temperature at 6 K is recognized as an antiferromagnetic-to-paramagnetic (AFM–PM) transition, which belongs to the first-order magnetic phase transition (FOMT). It is interesting that the HoBi compound with FOMT exhibits good thermal and magnetic reversibility. Furthermore, a large inverse and normal magnetocaloric effect (MCE) is found in HoBi single crystal in the H||[100] direction, and the positive ΔS M peak reaches 13.1 J/kg⋅K under a low field change of 2 T and the negative ΔS M peak arrives at –18 J/kg⋅K under a field change of 5 T. These excellent properties are expected to be applied to some magnetic refrigerators with special designs and functions.