Critical behavior and magnetocaloric effect of Gd65Mn35−xGex (x = 0, 5, and 10) melt-spun ribbons

Autor:	J. X. Min, X.C. Zhong, Dechang Zeng, Zongwen Liu, Z.G. Zheng
Rok vydání:	2012
Předmět:	Condensed Matter::Materials Science Magnetic anisotropy Paramagnetism Materials science Magnetic shape-memory alloy Ferromagnetism Condensed matter physics Magnetic refrigeration General Physics and Astronomy Ising model Critical exponent Amorphous solid
Zdroj:	Journal of Applied Physics. 112:033903
ISSN:	1089-7550 0021-8979
DOI:	10.1063/1.4740062
Popis:	Gd65Mn35−xGex (x = 0, 5, 10) alloy ribbons were prepared by melt-spinning. A fully amorphous structure was obtained for the alloys with x = 5 and 10, whereas, in melt-spun Gd65Mn35 ribbons, crystalline phases (α-Gd and GdMn2) precipitate in the amorphous matrix. The magnetic phase transition from ferromagnetic to paramagnetic is second order. The critical exponents are deduced from the Kouvel-Fisher method and scaling behavior. The obtained critical exponents are in agreement with the theoretical values of 3D Ising model. The Ising-like behavior suggests the presence of large anisotropy and short-range magnetic-coupling behavior. The maximum magnetic-entropy changes of the melt-spun alloys with x = 0, 5, and 10 for a magnetic field change from 0 to 5 T are 4.2, 4.1, and 4.5 Jkg−1 K−1, respectively. All three alloys have a broad temperature range of the magnetic-entropy peak, resulting in large refrigerant capacities.
Databáze:	OpenAIRE
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