Thermoelectric Properties of Bi-Sb-Te Prepared by Mechanical Alloying and the Vertical Bridgman Method
Year: 2007
Type: article
Abstract: Bi0.5Sb1.5Te3.0+x compounds with varying tellurium content (x=−0.10∼0.10) were prepared using mechanical alloying (MA) and the vertical Bridgman method (VBM), and compared their Hall coefficients, electrical resistivities and Seebeck coefficients at room temperature. In changing the tellurium content, it was possible to change the carrier concentration from 7.99×1024 to 1.52×1026m−3 for −0.10 < x < 0.00. In contrast, the carrier concentration was almost constant at 1.0×1025m−3 for 0.00 < x < 0.10. For samples with the same composition, it was observed that the carrier concentration of the VBM sample was approximately four times higher than that of the MA sample. The Seebeck coefficients for the two methods corresponded well with the relative carrier concentration, although the electrical resistivities of the VBM samples were found to vary because of preferred orientation. The maximum power factors for the MA and VBM samples were 3.52×10−3Wm−1K−2 at 1.23×1025m−3 (x=0.03), and 3.52×10−3Wm−1K−2 at 3.18×1025m−3 (x=0.00135), respectively. These results indicate that the difference in the carrier concentrations for two methods can be explained by the tellurium deficiency in samples prepared using the VBM.
DOI: 10.2497/jjspm.54.543
Author: Kazuhiro Hasezaki
Institutions: Shimane University, University of Shimane
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W1963958557