Influence of Co and Ni addition on the magnetocaloric effect in Fe88−2xCoxNixZr7B4Cu1 soft magnetic amorphous alloys

We have studied the magnetocaloric effect in a series of Fe88−2xCoxNixZr7B4Cu1 alloys. The partial substitution of Fe by Co and Ni leads to a monotonic increase in the Curie temperature (TC) of the alloys from 287 K for x=0 to 626 K for x=11. The maximum magnetic entropy change (ΔSMpk) at an applied field of 1.5 T, shows a value of 1.98 J K−1 kg−1 for x=8.25. The refrigerant capacity (RC) has maximum values near 166 J kg−1 (for x=0 and 2.75). These values place the present series of alloys among the best magnetic refrigerant materials, with an RC ∼40% larger than Gd5Si2Ge1.9Fe0.1 and ∼15% larger than Fe-based amorphous alloys.