Effects of crystallization treatment on the structure and magnetic properties of Gd65Fe25Zn10 alloy ribbons for magnetic refrigeration

• Published in: Journal of alloys and compounds Vol. 730; pp. 493 - 500
• Main Authors: Zhong, X.C., Mo, H.Y., Huang, X.W., Shen, X.Y., Feng, X.L., Jiao, D.L., Liu, Z.W.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05.01.2018
• Subjects: Crystallization; Gd65Fe25Zn10 alloys; Magnetocaloric effect; Melt-spun ribbons; Gd65Fe25Zn10 alloys; Melt-spun ribbons; Magnetocaloric effect; Crystallization
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2017.09.321

The structure and magnetic properties of Gd65Fe25Zn10 alloy ribbons prepared by melt-spinning followed by crystallization annealing were investigated. In the as-spun ribbons, there is a small amount of α-Gd nanocrystalline existed in the amorphous matrix. After crystallization treatment, besides the pre-precipitated α-Gd phase, GdFe2 and GdZn crystalline phases precipitated in turn in the amorphous matrix. The Curie temperature (TC) of the fully amorphous matrix is ∼250 K. Owing to α-Gd nanocrystalline precipitated in the amorphous matrix, a second order magnetic transition occurs near 288 K for both the as-spun and the as-annealed Gd65Fe25Zn10 ribbons. For a field change of 2 T, the maximum magnetic entropy change (−ΔSM)max for the as-spun and as-annealed ribbons are 1.56–2.31 and 3.83–4.06 J/(kg·K), while the values of refrigeration capacity (RCFWHM) are 224.0–387.0 and 149.5–158.0 J/kg, respectively. The as-spun Gd65Fe25Zn10 ribbons display relatively low (−ΔSM)max but the largest RCFWHM value due to the wide (−ΔSM) versus T curve peak. With negligible thermal/magnetic hysteresis losses, relative large (‒ΔSM)max and its peak temperature near room temperature, the Gd65Fe25Zn10 alloy ribbons can be used as the potential magnetic refrigeration material working at room temperature. •Gd65Fe25Zn10 alloys were prepared by melt-spinning followed by crystallization annealing.•TC is close to room temperature for as-annealed Gd65Fe25Zn10 alloys.•RC for Gd65Fe25Zn10 as-annealed alloys is higher than that of Gd5Si2Ge2 alloy.•Large (−ΔSM)max and negligible losses make the studied alloys suitable for magnetic refrigerant.