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Thermoelectric Properties of Bi-substituted Ca3Co4O9 Single Crystal

Published online by Cambridge University Press:  01 February 2011

M. Mikami ,
K. Chong  and
R. Funahashi
M. Mikami
Affiliation:
CREST, Japan Science and Technology Agency, Ikeda, Osaka 563–8577, Japan
K. Chong
Affiliation:
Osaka Electric-Communication Univ., Neyagawa, Osaka 572–0833, Japan
R. Funahashi
Affiliation:
CREST, Japan Science and Technology Agency, Ikeda, Osaka 563–8577, Japan National Institute of Advanced Industrial Science and Technology, Ikeda, Osaka 563–8577, Japan
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Abstract

We have grown single crystals of Bi-substituted Ca3Co4O9 by a solution method. The cationic ratio (Ca, Bi)/Co of the grown crystals measured by an energy dispersive X-ray spectrometer tended to exceed that of the starting ratio (Ca, Bi)/Co=3/4. For instance, the average cationic composition of the grown crystals was Ca:Bi:Co=3.3:0.3:4, while that of the starting material was Ca:Bi:Co=2.7:0.3:4. So, the crystallographic structure of the obtained crystals may correspond to the Ca2Co2O5 phase rather than the Ca3Co4O9 phase. Thermoelectric properties in the direction of ab-axis were measured at various temperatures. Seebeck coefficient (S) of Ca3.3Bi0.3Co4O9+δ is positive and increases with increasing temperature from 130 to 200 μV/K in a temperature region of 300–973 K. The electrical resistivity (ρ) of the sample is about 1.5 mΩcm at whole temperature region of 300–973 K. This value is lower than that of non-substituted Ca3Co4O9. The thermoelectric power factor (S2/ρ) is improved by the Bi-substitution, resulting from the reduction of resistivity.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 793: Symposium S – Thermoelectric Materials 2003 - Research and Applications , 2003 , S3.2
Copyright
Copyright © Materials Research Society 2004

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References

REFERENCES

1. Terasaki, I., Sasago, Y. and Uchinokura, K., Phys. Rev. B 56, 12685 (1997).Google Scholar
2. Fujita, K., Mochida, T. and Nakamura, K., Jpn. J. Appl. Phys. 40, 4644 (2001).Google Scholar
3. Li, S., Funahashi, R., Matsubara, I., Ueno, K. and Yamada, H., J. Mater. Chem. 9, 1659 (1999).Google Scholar
4. Funahashi, R., Matsubara, I., Ikuta, H., Takeuchi, T., Mizutani, U. and Sodeoka, S., Jpn. J. Appl. Phys. 39, L1127 (2000).Google Scholar
5. Takahata, K., Iguchi, Y., Tanaka, D., Itoh, T., and Terasaki, I., Phys. Rev. B 61, 12551 (2000).Google Scholar
6. Kawata, T., Iguchi, Y., Itoh, T., Takahata, K., and Terasaki, I., Phys. Rev. B 60, 10584 (1999).Google Scholar
7. Terasaki, I., Tsukada, I., and Iguchi, Y., Phys. Rev. B 65, 195106 (2002).Google Scholar
8. Li, S., Funahashi, R., Matsubara, I., Ueno, K., Sodeoka, S., and Yamada, H., Chem. Mater. 12, 2424 (2000).Google Scholar
9. Xu, G., Funahashi, R., Shikano, M., Matsubara, I., and Zhou, Y., Appl. Phys. Lett. 80, 3760 (2002).Google Scholar
10. Mikami, M., Ohtsuka, S., Yoshimura, M., Mori, Y., Sasaki, T., Funahashi, R., and Shikano, M., Jpn. J. Appl. Phys. 42, 3549 (2003).Google Scholar
11. Masset, A. C., Michel, C., Maignan, A., Hervieu, M., Toulemonde, O., Studer, F., and Raveau, B., Phys. Rev. B 62, 166 (2000).Google Scholar
12. Sugiyama, J., Brewer, J. H., Ansaldo, E. J., Itahara, H., Dohmae, K., Seno, Y., Xia, C., and Tani, T., Rhys. Rev. B 68, 134423 (2003).Google Scholar
13. Funahashi, R., unpublished data.Google Scholar
14. Shioyama, J., Horii, S., Otzshi, K., Sano, M., and Kishino, K., Jpn. J. Appl. Phys. 42, L194 (2003)Google Scholar
15. Koshibae, W, Tsutsui, K, and Maekawa, S, Phys. Rev. B 62, 6869 (2000).Google Scholar
16. Koshibae, W, and Maekawa, S, Phys. Rev. Lett. 87, 236603 (2001).Google Scholar