Excellent magnetocaloric effect at cryogenic temperature in amorphous (Fe35RE65) (RE = Er, Dy and Gd) alloys

Abstract

Heavy Rare Earth (HRE) elements have been selected for exploring the structural, magnetic and magnetocaloric performance of amorphous alloys (Fe35RE65) (RE = Er,Dy and Gd). These alloys undergo a second-order transition from ferromagnetic (FM) to paramagnetic (PM) state in the temperature range of liquid hydrogen (Tc < 70 k) for both Fe35Er65 and Fe35Dy65, and at room temperature (Tc = 273 k) for Fe35Gd65. Furthermore, For an applied magnetic field (H = 50 kOe), the entropy change (–ΔSM)max values are 9, 10.5 and 11.4 J/kg.K for Fe35Er65, Fe35Dy65 and Fe35Gd65, respectively. The observed relative cooling power (RCP) values of these amorphous alloys are 296, 302 and 312 J.kg−1 for Fe35Er65, Fe35Dy65 and Fe35Gd65 respectively. These findings make (HRE) – amorphous alloys promising materials for magnetic refrigeration applications with excellent magnetocaloric effects.