Magnetocaloric Effect of ${\rm Gd}_{55}{\rm Co}_{20}{\rm Al}_{25}$ Metallic Glass

Gd₅₅Co₂₀Al₂₅ rod samples with diameters of 1.5 and 3 mm were prepared by copper mold casting. XRD shows that the former is amorphous, while the latter has crystalline peaks due to the precipitates. Because of the different microstructure, the sample with 3 mm diameter has a relatively weaker thermal stability and smaller saturated magnetization, and is harder to be saturated, compared to the sample with 1.5 mm diameter. The characterization of magnetocaloric effect and refrigeration capacity shows that the amorphous sample with 1.5 mm diameter has a much better performance than the sample with 3 mm diameter. This comparison suggests that the quenched-in precipitates should be avoided in Gd-based metallic glasses for the magnetocaloric effect.