Large rotating magnetocaloric effect of textured polycrystalline HoB2 alloy contributed by anisotropic ferromagnetic susceptibility.

A large rotating magnetocaloric effect (RMCE) was always observed in the materials with anisotropic magnetisms, for example, ferromagnetism vs antiferromagnetism or paramagnetism, at different crystallographic directions. In this work, anisotropic ferromagnetic susceptibility is utilized to implement low-field (≤2 T) large RMCE in the textured polycrystalline HoB₂ alloy. The x-ray diffraction and scanning electron microstructure results reveal that the arc-melted HoB₂ exhibits preferred grain orientation along the solidification direction. The measured rotating magnetic entropy changes (−ΔS_R) and refrigeration capacity are 6.27 J/kg K and 73.7 J/kg, respectively, under the magnetic field change of 1 T. They are comparable with those of other materials contributed by anisotropic magnetisms. Our results suggest that the polycrystal HoB₂ alloy is a promising material for practical application of magnetic refrigeration based on RMCE. [ABSTRACT FROM AUTHOR]