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Synthesis and High Temperature Thermoelectric Properties of Alkaline-Earth Metal Hexaborides MB6 (M=Ca, Sr, Ba)

Published online by Cambridge University Press:  01 February 2011

Masatoshi Takeda
Affiliation:
Department of Mechanical Engineering, Nagaoka University of Technology, Kamitomioka, Nagaoka, 940–2188, Japan
Yosuke Kurita
Affiliation:
Department of Mechanical Engineering, Nagaoka University of Technology, Kamitomioka, Nagaoka, 940–2188, Japan
Keisuke Yokoyama
Affiliation:
Department of Mechanical Engineering, Nagaoka University of Technology, Kamitomioka, Nagaoka, 940–2188, Japan
Takahiro Miura
Affiliation:
Department of Mechanical Engineering, Nagaoka University of Technology, Kamitomioka, Nagaoka, 940–2188, Japan
Tsuneo Suzuki
Affiliation:
Extreme Energy-Density Research Institute, Nagaoka University of Technology, Kamitomioka, Nagaoka, 940–2188, Japan
Hisayuki Suematsu
Affiliation:
Extreme Energy-Density Research Institute, Nagaoka University of Technology, Kamitomioka, Nagaoka, 940–2188, Japan
Weihua Jiang
Affiliation:
Extreme Energy-Density Research Institute, Nagaoka University of Technology, Kamitomioka, Nagaoka, 940–2188, Japan
Kiyoshi Yatsui
Affiliation:
Extreme Energy-Density Research Institute, Nagaoka University of Technology, Kamitomioka, Nagaoka, 940–2188, Japan
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Abstract

Polycrystalline alkaline-earth hexaborides (MB6: M =Ca, Sr, Ba) were synthesized and their thermoelectric and transport properties were examined to discuss their possibility as high temperature thermoelectric materials. Hall measurements showed that carrier concentration of the BaB6 was the highest among the three hexaborides and that of CaB6 was the lowest. Substitution of part of the alkaline earth metals with one of the others changed the carrier concentration of the hexaboride. As the carrier concentration increased, Seebeck coefficient increased and electrical conductivity decreased. These results suggest that the thermoelectric properties of the divalent hexaborides depend largely on the carrier concentration, and optimum carrier concentration which gives maximum power factor was estimated to be approximately 2x1026 m−3. Consequently, such a substitution enables us to control Seebeck coefficient and electrical conductivity of the hexaborides, and will also be effective to reduce the lattice heat conduction due to the alloying effect. A thermoelectric device was fabricated using SrB6 and boron carbide thin films as n-type and p-type elements, respectively. To the best of our knowledge, this is the first demonstration of a thermoelectric device composed of only boron-rich solids.

Type
Research Article
Copyright
Copyright © Materials Research Society 2004

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References

REFERENCES

1. Wood, C., in Boron-Rich Solids, AIP Conf. Proc. 140, ed. by Emin, D., Aselage, T. L., Beckel, C. L., Howard, I. A. and Wood, C., (Am. Inst. Phys., New York, 1985) pp. 362372.Google Scholar
2. Gunjishima, I., Akashi, T., and Goto, T., Mater. Trans. 42, 1445 (2001).Google Scholar
3. Suematsu, H., Kitajima, K., Ruiz, I., Kobayashi, K., Takeda, M, Shimbo, D., Suzuki, T., Jiang, W., and Yatsui, K., Thin Solid Films, 407, 132 (2002).Google Scholar
4. Aselage, T. L., Emin, D., and McCready, S. S., Phys. Rev. B 64, 54302 (2001).Google Scholar
5. Werheit, H., Schmechel, R., Fueffel, V., and Lundström, T., J. Alloys Comp. 262, 372 (1997).Google Scholar
6. Nakayama, T., Shimizu, J., and Kimura, K., J. Solid State Chem. 154, 13 (2000).Google Scholar
7. Liu, C. H., Materials Letters, 49, 308 (2001).Google Scholar
8. Hwang, S., Yang, K., Dowben, P. A., Ahmad, A. A., Ianno, N. J., Li, J. Z., Lin, J. Y., Jiang, H. X., and Mcllroy, D. N., Appl. Phys. Lett. 70, 1028 (1997).Google Scholar
9. Kuhlmann, U., Werheit, H., Dose, T., and Lundström, T., J. Alloys Comp., 186, 187 (1992).Google Scholar
10. Imai, Y., Mukaida, M., Ueda, M., Watanabe, A., Intermetallics, 9, 721 (2001).Google Scholar
11. Takashima, N., Kawano, J., Mori, K., Nishi, Y., Miyazawa, Y., and Matsushita, J., in Proc. 44th Int. SAMPE Symp. ed. by Cohen, L. J., Bauer, J. L. and Davis, W. E. (SAMPE, Cavina, CA, 1999) pp. 24062415.Google Scholar
12. Giannò, K., Sologubenko, A. V., Ott, H. R., Bianchi, A. D., and Fisk, Z., J. Phys.: Condens. Matter, 14, 1035 (2002).Google Scholar
13. Takeda, M., Domingo, F., Miura, T., and Fukuda, T., in Thermoelectric Materials 2001 – Research and Applications, ed. by Nolas, G. S., Johnson, D. C., and Mandrus, D. G. (Mater. Res. Soc. Proc. 691, Warrendale, PA, 2002) pp. 209214.Google Scholar
14. Takeda, M., Fukuda, T., Domingo, F., and Miura, T., J. Solid State Chem., in press.Google Scholar
15. Takeda, M., Fukuda, T., and Miura, T., in Proc. 21st Int. Conf. Thermoelectrics, ed. by Caillat, T. and Snyder, J. (IEEE, Piscataway, NJ, 2002) pp. 173176.Google Scholar
16. Miura, T., Yokoyama, K., and Takeda, M., Adv. in Tech. of Mat. and Mat. Proc. J. (ATM), 5, 70 (2003).Google Scholar
17. Shimotori, Y., Yokoyama, M., Harada, S., Masugata, K., and Yatsui, K., J. Appl. Phys., 63, 968 (1988).; Jpn. J. Appl. Phys., 28, 468 (1989).Google Scholar
18. Kang, X. D., Masugata, K., and Yatsui, K., Jpn. J. Appl. Phys., 33, 1155 (1994).Google Scholar
19. Kitajima, K., Suzuki, T., Jiang, W., and Yatsui, K., Jpn. J. Appl. Phys., 40, 1030 (2001).Google Scholar
20. Suematsu, H., Kitajima, K., Suzuki, T., Jiang, W., Yatsui, K., Kurashima, K., and Bando, Y., Appl. Phys. Lett., 80, 1153 (2002).Google Scholar
21. Souma, S., Komatsu, H., Takahashi, T., Kaji, R., Sakaki, T., Yokoo, Y., and Akimitsu, J., Phys. Rev. Lett., 90, 027202 (2003).Google Scholar