Large magnetic entropy change and adiabatic temperature rise of a Gd 55Al20Co20Ni5 bulk metallic glass

Abstract

Gd55Al20Co20Ni5 bulk metallic glass (BMG) was synthesized by minor Ni substitution for Co in the Gd 55Al20Co25 BMG in which excellent glass forming ability (GFA) and magneto-caloric effect were reported previously. The Gd 55Al20Ni20Co5 amorphous rod has a similar GFA to the Gd55Al20Co25 BMG but exhibits better magnetic properties. The peak value of magnetic entropy change (-ΔSm peak) of the Gd55Al 20Co20Ni5 BMG is 9.8 Jkg-1 K -1. The field dependence of -ΔSm peak follows a -ΔSmpeak-H0.85 relationship. The adiabatic temperature rise of the rod is 4.74K under 5 T and is larger than of other BMGs previously reported. The improved magnetic properties were supposed to be induced by the enhanced interaction between 4f electron in the rare-earth and 3d electron in the transition metal elements by means of a minor Ni substitution for Co.