Large magnetocaloric effect and enhanced magnetic refrigeration in ternary Gd-based bulk metallic glasses

Abstract

The magnetocaloric effect and refrigeration capacity (RC) of Gd55Co20Al25 and Gd55Ni25Al20 bulk metallic glasses (BMGs) have been investigated. Large magnetic entropy changes ΔSM of 11.2 and 10.8 J kg−1 K−1 and large RC values of 846 and 920 J kg−1 are obtained for Gd55Co20Al25 and Gd55Ni25Al20, respectively, at a field change of 7 T. The RC value (640 J kg−1 at 5 T or 920 J kg−1 at 7 T) of Gd55Ni25Al20 BMG is larger than that reported for all magnetocaloric materials, including crystalline and amorphous materials measured under the same conditions. The large RC value is due to the broad ΔSM peak (more than 100 K), which is caused by the disordered structure of an amorphous material. The large ΔSM and RC values make these Gd-based ternary BMGs attractive candidates for magnetic refrigeration applications.