Magnetic phase transition and magnetocaloric effect in amorphous Gd52Fe28B20 alloy

Magnetic phase transition and magnetocaloric effect in the amorphous Gd52Fe28B20 alloy are exhaustively explored. The melt spinning technique was employed to produce the amorphous alloy. Considering the Landau theory and Banerjee criterion, the nature of the magnetic phase transition (MPT) follows a second order MPT at the Curie temperature (TC) from ferromagnetic to paramagnetic states. The Maxwell thermodynamic relation was used to calculate the maximum isothermal entropy change (-Delta S-M). This alloy exhibits wide peaks in entropy versus temperature curves, which is advantageous for enhancing the relative cooling power (RCP). The RCP of Gd52Fe28B20 was found to be similar to 190 J kg(-1) (at T-C = 260 K, mu H-0 = 2 T), the value similar to that obtained in pure Gd (at T-C = 293 K, mu H-0 = 2 T). Additionally, we provide a phenomenological model related to the theoretical assessment of the magnetocaloric effect. The dependence of theoretical parameters on temperature and magnetic field was established through rigorous analysis. The accuracy of these theoretical predictions was assessed by comparing them to experimental results. Consequently, this alloy is appropriate for use near the ordering temperature of 260 K, which bodes well for the development of novel magnetic refrigerants for active cooling applications.