Publication Date:
2016-03-03
Description:
A class of biphase nanocrystalline/amorphous Gd (50+5 x ) Al (30−5 x ) Co 20 ( x = 0, 1, 2) microwires fabricated directly by melt-extraction is reported. High resolution transmission electron microscopy and Fourier function transform based analysis indicate the presence of a volume fraction (∼20%) of ∼10 nm sized nanocrystallities uniformly embedded in an amorphous matrix. The microwires possess excellent magnetocaloric properties, with large values of the isothermal entropy change (−Δ S M ∼ 9.7 J kg −1 K −1 ), the adiabatic temperature change (Δ T ad ∼ 5.2 K), and the refrigerant capacity ( RC ∼ 654 J kg −1 ) for a field change of 5 T. The addition of Gd significantly alters T C while preserving large values of the Δ S M and RC. The nanocrystallites allow for enhanced RC as well as a broader operating temperature span of a magnetic bed for energy-efficient magnetic refrigeration.
Print ISSN:
0003-6951
Electronic ISSN:
1077-3118
Topics:
Physics
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