Magnetocaloric Properties and Phenomenological Model in Amorphous Eu0.8Au0.2 Alloy

Amorphous Eu0.8Au0.2 alloy was prepared by liquid quenching with the piston-and-anvil technique. The magnetic properties were identified by exploiting the magnetization data. The magnetocaloric effect was evaluated by calculating the magnetic entropy changes (- increment S-M) from the magnetization data sets measured at various temperatures and applied magnetic fields. From the Arrott plots, it is found that the amorphous alloy exhibits a second-order magnetic transition from ferromagnetic to paramagnetic state at the Curie temperature T-C = 80 K. The magnetic entropy change - increment S-M in the amorphous Eu0.8Au0.2 alloy is found to be 4.60 J/K.kg under a magnetic field of 0-4 T with a large relative cooling power of 663.70 J/kg. In addition, a phenomenological model based on a theoretical evaluation of the magnetocaloric effect was presented. The experimental results were found to be in good agreement with the theoretical predictions.