Near room temperature magnetocaloric properties of melt-spun Gd100−xBx (x=0, 5, 10, 15, and 20 at%) alloys

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 Gd100−xBx (x=0, 5, 10, 15, and 20 at%) alloys were prepared by melt spinning. With the decrease in Gd/B ratio, Curie temperature (TC) 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, (−ΔSM)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 Gd85B15 and Gd80B20 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 Gd80B20 alloy. The near room temperature magnetocaloric properties of melt-spun Gd100−xBx (0≤x≤20) alloys were found to be comparable to few first-order transition based magnetic refrigerants.

► The magnetocaloric properties of melt-spun Gd100−xBx (x=0, 5, 10, 15 and 20) alloys were examined with the aim to explore their potential application as magnetic refrigerants near room temperature. ► The lattice parameters (a and c) of melt-spun Gd are unchanged with the addition of B. ► The melt-spun alloys show no change in TC (∼293 K) upon alloying Gd with B up to 20 at% . ► The saturation magnetization (at 275 K) decreases with increasing addition of B from ∼100 emu/g (Gd) to ∼78 emu/g (Gd80B20 alloy). Negligible magnetic hysteresis was observed in these alloys. ► The peak value of magnetic entropy change, (−ΔSM)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 Gd85B15 and Gd80B20 alloys.