Effect of Small Amount of Zn Additions on the Magnetocaloric Properties of Gd5Si2Ge2 Alloy
The structural and magnetic property of Gd5Si1.99Ge2Zn0.01and Gd5Si2Ge2 alloys prepared by arc-melting the starting materials with commercial available purity (99.95wt%) was investigated by x-ray diffraction and Vibrating Sample Magnetometer. The result shows that the Gd5Si1.99Ge2Zn0.01 alloy has monoclinic phase with Gd5Si2Ge2-type structure. The polymorphic orthorhombic phase with Gd5Si4-type structure coexists with the monoclinic phase in Gd5Si2Ge2 alloy. The addition of small Zn element in Gd5Si2Ge2 alloy results in a considerable enhancement of its magnetocaloric effect. The maximum magnetic entropy change rapidly increases from 5.03J/(kg K) to 20.70J/(kg K) for a magnetic field change from 0 to 1.5T. The magnetic order temperature is 278K in Gd5Si1.99Ge2Zn0.01 alloy and 278.5K in Gd5Si2Ge2 alloy respectively. The magnetocaloric effect of Gd5Si2Ge2 with the small addition of Zn is significantly improved.
Kunyuan Gao, Shaoxiong Zhou, Xinqing Zhao
X. Z. Wang et al., "Effect of Small Amount of Zn Additions on the Magnetocaloric Properties of Gd5Si2Ge2 Alloy", Materials Science Forum, Vol. 685, pp. 307-310, 2011