Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1612181 | Journal of Alloys and Compounds | 2014 | 6 Pages |
Abstract
The potential thermoelectric and magnetic application of clathrate materials with rare-earth doping is the focus of much of the recent research activity in the synthetic material physics and chemistry. A series of clathrate samples with the chemical formula Ba8âxYbxSi30Ga16 (x = 0, 0.5, 0.7, 1 and 1.5) were prepared by combining arc melting, ball milling and spark plasma sintering (SPS) techniques. X-ray diffraction and scanning electronic microscopy combined with energy-dispersive X-ray spectroscopy (EDS) analysis showed the dominant phase to be the type-I clathrate. Whereas, X-ray structural refinement and EDS analysis indicated that some Yb atoms enter the clathrate lattice to replace Ba at 2a sites, while other Yb atoms are oxidized as Yb2O3 precipitated around grain boundaries. The solid solubility of Yb into clathrate lattice yielded x â¼Â 0.3. Comparative analysis between Yb-doped and Yb-free clathrates showed that the thermal conductivity decreases with Yb-doping. Consequently, thermoelectric figure of merit ZT significantly increased.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
Lihua Liu, Feng Li, Yuping Wei, Ning Chen, Shanli Bi, Hongmei Qiu, Guohui Cao, Yang Li,