Conference paper
Thermoelectric Properties and Microstructure of Modified Novel Complex Cobalt Oxides Sr3RECo4O10.5 (RE = Y, Gd)
We report on the high-temperature thermoelectric properties and microstructure of modified novel complex cobalt oxides Sr3RECo4O10.5 (RE = Y, Gd), in which the Sr- and Co-sites are partly substituted by Ca and Ga, respectively. We have found that the sample with RE = Gd shows a significant higher electrical conductivity (sigma) than the RE = Y sample, while their Seebeck coefficients (S) remain almost the same over the whole measured temperature range.
With Ga substituting for Co, S is enhanced and further increased by the dually doping with Ca at the Sr-site, leading to an improvement of the thermoelectric power factor (sigma S-2). At 1150 K, the highest sigma S-2 value attains for the Sr2CaGdCo3.9Ga0.1O10.5 sample about 60 mu Wm(-1)K(-2), which is 8 times larger than the Sr3GdCo4O10.5 counter-part.
Interestingly, although microstructure shows a clear evolution of the grains for the Ga and Ca doped-sample resulting in a substantial decrease in porosity, its thermal diffusivity exhibits a lower value then the non-doped one, particularly in high temperature region. © 2012 American Institute of Physics
Language: | English |
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Publisher: | American Institute of Physics |
Year: | 2012 |
Pages: | 339-342 |
Proceedings: | 9th European Conference on Thermoelectrics |
ISSN: | 15517616 and 0094243x |
Types: | Conference paper |
DOI: | 10.1063/1.4731566 |
ORCIDs: | Van Nong, Ngo and Pryds, Nini |