Magnetic and magnetocaloric properties of ternary Gd–Co–Al bulk metallic glasses

Bulk metallic glasses (BMGs) with compositions of Gd55CoxAl45−x (15 ≤ x ≤ 30) and Gd60CoyAl40−y (15 ≤ y ≤ 30) were synthesized by an injection casting technique. Temperature dependence of magnetization of the BMGs indicates that their Curie temperatures can be tailored between 96 and 143 K by varying Gd and Co concentration. The magnetic entropy changes of the BMGs are greater than 9.0 J/kg K except for the Gd55Co30Al15 glass that exhibits a reduced magnetization due to its large Co content. The relative cooling powers of the BMGs are greater than those of any other crystalline compounds and decrease with the increasing Co content.

Research highlights
► The Curie temperatures of Gd–Co–Al bulk metallic glasses (BMGs) in the Gd-rich end can be tailored by varying Gd and Co concentration.
► Both the moments of Co calculated from Cruie–Weiss fit and the saturation magnetization at 2 K confirm that Co reserves its moment even when its content in the BMGs is as low as 15%.
► The magnetic entropy changes of the BMGs are greater than 9.0 J/kg K with the field from 0 to 50 kOe field. The relative cooling powers (RCPs) of BMGs are greater than those of any other crystalline compounds and decrease with the increasing of Co content.