Magnetic properties and large magnetocaloric effect in Gd–Ni amorphous ribbons for magnetic refrigeration applications in intermediate temperature range

Amorphous Gd68−xNi32+x (x = −3, 0, 3) ribbons were prepared by melt-spinning method. The crystallization onset temperatures Tx1 for Gd68−xNi32+x amorphous ribbons with x = −3, 0, and 3 are 561, 568, and 562 K, respectively. All the samples undergo the second-order magnetic transition at temperatures between ∼122 (x = −3 and 3) and 124 K (x = 0). The Curie temperature TC does not change with the composition significantly. The maximum isothermal magnetic entropy changes (−ΔSM)max of Gd71Ni29, Gd68Ni32, and Gd65Ni35 amorphous ribbons for a magnetic field change of 0–5 T were 9.0, 8.0, and 6.9 J kg−1 K−1, respectively. Large values of the refrigerant capacity (RC) were obtained in these ribbons. For example, Gd71Ni29 amorphous ribbon has a maximum RC value of 724 J kg−1. Large magnetic entropy change and RC values together with high stability enable the Gd71Ni29 amorphous alloy a competitive candidate among the magnetic refrigeration materials working at temperatures near 120 K.

► We report that the first crystallization temperature Tx1 of Gd68−xNi32+x amorphous ribbons with x = −3, 0, and 3 were 561, 568, and 562 K, respectively. ► All the samples underwent the second-order magnetic transitions at temperatures between ∼122 (x = −3 and 3) and 124 K (x = 0). ► The maximum isothermal magnetic entropy changes (−ΔSM)max of Gd71Ni29, Gd68Ni32, and Gd65Ni35 amorphous ribbons with a magnetic field change of 0–5 T were 9.0, 8.0, and 6.9 J kg−1 k−1, respectively. ► Large refrigerant capacity (RC) values were also obtained in these ribbons. For example, Gd71Ni29 amorphous ribbon has a maximum RC value of 724 J kg−1. ► Large magnetic entropy change and RC values, as well as high stability enable Gd71Ni29 amorphous ribbon to be a competitive candidate among the magnetic refrigeration materials working at temperatures near 120 K.