Achieving an enhanced magneto-caloric effect by melt spinning a Gd55Co25Al20 bulk metallic glass into amorphous ribbons

The magneto-caloric effect (MCE) and microstructure of the Gd55Co25Al20 metallic glasses were studied in the present work. It was found that the amorphous ribbons exhibit a peak value of magnetic entropy change (−ΔSmpeak) up to 39.5% higher than that of the bulk metallic glass (BMG) under a magnetic field of 1 T. The mechanism for the enhanced MCE of amorphous ribbons was investigated and the dependence of magneto-caloric behaviors on the microstructure of the glassy alloys was revealed. The larger −ΔSmpeak as well as refrigeration capacity under low magnetic field, together with the higher heat exchange efficiency of the ribbons, indicates that the amorphous ribbons could be more suitable candidates as the magnetic refrigerants rather than the BMG.