Effect of Fe substitution on magnetocaloric effects and glass-forming ability in Gd-based metallic glasses

In this work, we report on the systematic variation of the glass-forming ability (GFA) and magnetocaloric effect (MCE) in Gd55Co20-xAl24Si1Fex (x = 0, 1, 2, 3, 4 and 5 at%) metallic glasses (MGs), which are potential candidates for magnetocaloric cooling applications. The addition of Fe broadens the full width of half maximum of magnetic entropy change (δTFWHM), thereby greatly increases the refrigeration capacity (RC). Accordingly, the δTFWHM as large as 118 K, magnetic entropy change |ΔSM| of 7.26 J kg−1K−1 at 130 K, and corresponding large RC of 857 J kg−1 under applied field of 5 T are obtained for the composition with 5 at% Fe substitution. By increasing the atomic fraction of Fe dopants, the Curie temperature TC increases systematically at the same time. Such high GFA of novel Gd-based MGs with large MCE makes them attractive candidates for magnetic refrigeration applications in the future.