The magnetic properties and magnetocaloric effects of amorphous and crystalline GdCuAl ribbons have been experimentally studied. The amorphous ribbon exhibits a superparamagnetic behaviour, as demonstrated by the appearance of a maximum in the in-phase linear susceptibility chi(1)' and a minimum in the in-phase nonlinear susceptibility chi(3)' at similar to 25 K. In the high temperature range, chi(1)' and chi(3)' vary following the Curie-Weiss law and the 1/T-3-law, respectively. For crystalline GdCuAl; ribbons, a ferromagnetic-to-paramagnetic second-order phase transition takes place around 81 K. The maximum magnetic entropy change and refrigerant capacity are as high as similar to 10.1 J kg(-1) K-1 and 460 J kg(-1), respectively, for a field change of 0-5 T. These features make crystalline GdCuAl an attractive candidate for a low-temperature magnetic refrigerant.
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