Enhanced magnetocaloric effect in rapidly solidified HoNi2 melt-spun ribbons

Abstract

The structural, magnetic and magnetocaloric properties of HoNi2 melt-spun ribbons were investigated by X-ray diffraction, magnetization and specific heat measurements. The as-solidified ribbons samples produced are single phase with the cubic MgCu2-type crystal structure of the Laves phase (C15; space group Fd-3m), and a Curie temperature TC of 13.9 K. For a magnetic field change μoΔH of 5 T (2 T) applied along the ribbon length, the produced ribbon samples show a maximum magnetic entropy change ΔSMpeak of −27.2 (−16.9) J kg−1 K−1, a full-width at half-maximum δTFWHM for the ΔSM(T) curve of 19 (11) K, and a refrigerant capacity, determined from the area below δTFWHM the ΔSM(T) curve, of 388 (145) Jkg−1; the adiabatic temperature change ΔTad at 2 T is 6.7 K. Whereas crystal structure and intrinsic magnetic properties are in good agreement with the experimental data previously reported in literature for bulk polycrystalline alloys, the magnetocaloric parameters at 2 T are markedly superior owing to the favorable combination of partial texture with the anisotropic behavior of magnetization.