Magnetocaloric effect in Er[formula omitted]Gd[formula omitted]Al2 ([formula omitted]) alloys

Abstract

Measurements of magnetization (M) were performed on a series of Er1−xGdxAl2 (x= 0.1, 0.25, and 0.5) alloys. ErAl2 and GdAl2 are ferromagnets with the Curie temperatures (TC) of 14 K and 168 K, respectively. Er1−xGdxAl2 also showed a ferromagnetic order at TC= 21 K for x= 0.1, 57 K for x= 0.25, and 89 K for x= 0.5. Upon cooling, M(B) curves of Er1−xGdxAl2 for 0.1≤x≤0.5 exhibited a metamagnetic behavior. The field cooled M for Er1−xGdxAl2 increased below 30 K, indicating a spin-reorientation transition. The magnetic entropy change (ΔSm) for x=0.1 peaked at TC, while a peak or kink was observed for x= 0.25 and 0.5 in ΔSm near 25 K, distinct from a ferromagnetic order. The spin-reorientation due to the Gd substitution is attributed to the magnetic properties and broadened ΔSm(T) curves for Er1−xGdxAl2 alloys.