Microstructure and thermoelectric properties of tungsten trioxide ceramics doped with a low amount of terbium dioxide

• Published in: Journal of materials science. Materials in electronics 2013-10, Vol.24 (10), p.4001-4007
• Main Authors: Gan, Yingjie, Dong, Xiang, Peng, Shujie, Dong, Liang, Wang, Yu
• Format: Article
• Language: English
• Subjects: Applied sciences; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Dioxides; Electrical conductivity; Electrical resistivity; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in multilayers, nanoscale materials and structures; Electronics; Exact sciences and technology; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Materials; Materials Science; Optical and Electronic Materials; Physics; Resistivity; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thermoelectricity; Tungsten; Tungsten oxides
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-013-1353-5

The effect of the nonstoichiometric compound terbium dioxide (Tb 4 O 7 ) on the thermoelectric properties of tungsten trioxide (WO 3 ) ceramics was investigated. Among the sintered ceramics, the sample doped with 0.1 mol% Tb 4 O 7 showed the maximum grain size and density. Doping with Tb 4 O 7 also increased the electrical conductivity ( σ ) of the ceramics by about two orders of magnitude, and the sample doped with 0.1 mol% Tb 4 O 7 showed the highest electrical conductivity. The absolute value of Seebeck coefficient (| S |) of the doped samples increased as well. Consequently, the power factor ( σs 2 ) markedly increased. The sample doped with 2.0 mol% Tb 4 O 7 demonstrated the maximum σs 2 of 2.88 μW m −1  K −2 at 973 K, which was larger than the highest recorded σs 2 for WO 3 ceramics (2.71 μW m −1  K −2 at 1,023 K). In addition, the low-doped sample (0.1 mol%) exhibited excellent thermoelectric properties.