Magnetocaloric effect in Gd-based Gd60FexCo30−xAl10 metallic glasses

Magnetocaloric effect and refrigerant capacity of Gd-based Gd₆₀Fe_xCo_30−xAl₁₀ metallic glasses are investigated for x = 0, 10 , 20 and 30. It is found that the non-linearity of saturation magnetization in crystalline Co-Fe binary alloys can be transferred to the quaternary metallic glass. Whereas the magnetocaloric specific values of Gd₆₀Co₃₀Al₁₀ are comparable in magnitude with those of other Gd-based metallic glasses, Fe addition leads to an increase of the saturation magnetization and refrigerator capacity with a maximum for x = 20. Simultaneously, the temperature of maximum isothermal change of magnetic entropy T_ΔSmax increases from 145 to 200 K with increasing Fe-content and also the halfwidth ΔT_Smax/2 of the ΔS-T-curve is considerably broadened. Furthermore, the effect of thermal treatment slightly above the first crystallization event on the magnetocaloric effect are investigated, showing a lowering of the working temperature in the first place.