Enhancing the Figure of Merit in Te-doped FeSb2 through nanostructuring
| Autor: | Pokharel, M., Zhao, H. Z., Koirala, M., Ren, Z. F., Opeil, C. |
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| Rok vydání: | 2013 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | We study the thermoelectric properties of Te-doped FeSb2 nanostructured samples. Four samples of stoichiometry FeSb1.84Te0.16 were prepared by a hot press method at temperatures of 200, 400, 500, and 600 oC. Te-doping enhances the dimensionless figure of merit (ZT) on FeSb2 via two mechanisms. First, a semiconductor to metal transition is induced, which enhances the value of the power factor at low-temperatures. Second, the thermal conductivity, which was already reduced in nanostructured FeSb2 samples, is further reduced by increased point defect scattering through the n type substitution of Sb site by Te atom. The combined effect results in a ZT = 0.022 at 100 K, an increase of 62% over the ZT value for the optimized Te-doped single crystal sample. Hall coefficient and electrical resistivity measurements reveal a decreased mobility and increased concentration of the carriers in the doped sample. Comment: 14 pages, 6 figures |
| Databáze: | arXiv |
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