Near room temperature magnetocaloric properties of melt-spun Gd 100− xB x ( x=0, 5, 10, 15, and 20 at%) alloys

Abstract

The magnetocaloric properties of melt-spun Gd–B alloys were examined with the aim to explore their potential application as magnetic refrigerants near room temperature. A series of Gd 100− x B x ( x=0, 5, 10, 15, and 20 at%) alloys were prepared by melt spinning. With the decrease in Gd/B ratio, Curie temperature ( T C ) remains constant at ∼293 K, and saturation magnetization, at 275 K, decreases from ∼100 to ∼78 emu/g. Negligible magnetic hysteresis was observed in these alloys. The peak value of magnetic entropy change, (−Δ S M ) max, decreased from ∼9.9 J/kg K (0–5 T) and ∼5.5 J/kg K (0–2 T) for melt-spun Gd to ∼7.7 J/kg K (0–5 T) and ∼4.0 J/kg K (0–2 T), respectively for melt-spun Gd 85B 15 and Gd 80B 20 alloys. Similarly, the refrigeration capacity ( q) decreased monotonously from ∼430 J/kg (0–5 T) for melt-spun Gd to ∼330 J/kg (0–5 T) for melt-spun Gd 80B 20 alloy. The near room temperature magnetocaloric properties of melt-spun Gd 100− x B x (0≤ x≤20) alloys were found to be comparable to few first-order transition based magnetic refrigerants.