Influence of Ge addition on the magnetocaloric effect of a Co-containing Nanoperm-type alloy

The influence of the partial substitution of B by Ge on the magnetocaloric response of Fe78Co5Zr6B10Cu1 is studied. Ge addition produces a reduction in the temperature at which the peak entropy change takes place, as well as a slight decrease in the magnitude of the peak, ∣ΔSMpk∣. The refrigerant capacity, RC, and its field dependence is also analyzed: although Ge addition increases RC of the Co-containing alloy, the largest RC value corresponds to the Co- and Ge-free alloy. This will be discussed on the basis of the recently proposed universal curve for the magnetic entropy change, which is also followed by the FeZrBCu(Co,Ge) alloy series.