Magnetocaloric effect of melt-extracted high-entropy Gd₁₉Tb₁₉Er₁₈Fe₁₉Al₂₅ amorphous microwires

In this paper, the magnetocaloric effect (MCE) of a high-entropy Gd₁₉Tb₁₉Er₁₈Fe₁₉Al₂₅ amorphous microwires fabricated by melt-extracted method are investigated systematically. These microwires exhibit a second-order phase transition from ferromagnetic to paramagnetic states at the Curie temperature of 97 K. The zero-field-cooling (ZFC) and field-cooling (FC) magnetization curves are irreversible when the temperature lower than the Curie temperature due to the spin glassy freezing behavior. The peak magnetic entropy change (ΔS_M ^pk) for a field change from 0 to 5 T reaches ~5.94 J/kg∙K. In accordance to two criteria refrigerant capacity, the values of refrigerant capacity (RC) and relative cooling power (RCP) reach ~569 J/kg and ~733 J/kg at a field change of 5 T, respectively. These results suggest that the melt-extracted Gd₁₉Tb₁₉Er₁₈Fe₁₉Al₂₅ microwires exhibit good MCE and have great potential to use as one kind of high temperature magnetic refrigeration material.