Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-11-23T17:59:07.318Z Has data issue: false hasContentIssue false

Thermoelectric properties of icosahedral cluster solids – Metallic-Covalent Bonding Conversion and Weakly Bonded Rigid Heavy Clusters

Published online by Cambridge University Press:  01 February 2011

Kaoru Kimura
Affiliation:
[email protected], The University of Tokyo, Department of Advanced Materials Science, 502, Kiban-toh, 5-1-5 Kashiwanoha, Kashiwa-shi,, Chiba 277-8561, N/A, N/A, Japan, +81-4-7136-5456, +81-4-7136-3758
Junpei Tamura Okada
Affiliation:
[email protected], The University of Tokyo, Department of Applied Physics, Japan
Hongki Kim
Affiliation:
[email protected], The University of Tokyo, Department of Advanced Material Science, Japan
Takehito Hamamatsu
Affiliation:
[email protected], The University of Tokyo, Department of Advancec Materials Sceince, Japan
Tomohiro Nagata
Affiliation:
[email protected], The University of Tokyo, Department of Materials Science, Japan
Kazuhiro Kirihara
Affiliation:
[email protected], National Institute of Advanced Industrial Science and Technology, Nanoarchitectonics Research Center
Get access

Abstract

Boron- or Aluminum-rich icosahedral cluster solids (ICS) consist mainly of B12 or Al12 icosahedral clusters. In the ICS, a slight change of the structure or environment of icosahedral cluster can cause metallic-covalent bonding conversion, which can cause that the electrical conductivity σ and the Seebeck coefficient S can be as high as those of metals and semiconductors, respectively. Five-fold symmetry of the icosahedral cluster does not match with the translational symmetry of a crystal, consequently makes lower thermal conductivity with complex structure. For these reasons, ICS are promising candidates for thermoelectric materials.

Using MEM/Rietvelt method, we successfully obtained the clear image of the electron density distribution for alpha-AlReSi approximant crystal. The bond strength distributes widely from weak metallic to strong covalent bond, and the intra-cluster bonds are stronger than the inter-cluster ones. This means that alpha-AlReSi is located at the intermediate state of molecular, metallic- and covalent-bonded solids. Composition dependences of atomic density and quasi-lattice constant for AlPdRe icosahedral quasicrystals show the above situation is the same in the quasicrystals. The thermoelectric figure of merit Z and the effective mass m* of AlPdRe quasicrystals can be increased by strengthening the intra- and weakening the inter-cluster bonds. According to this scenario, Z was improved by a factor of 1.5 by substitution of Ru for Re.

In β-rhombohedral boron, several interstitial sites, which have space large enough to accommodate foreign atoms, are known. For the V doped sample, in which V atoms mainly occupy A1 site, the metallic-covalent bonding conversion may occur, σ is increased very much, S is decreased even to negative value and kappa is decreased. The maximum and n-type ZT value is obtained and is approaching to that of B4C, which is considered to have the largest and p-type ZT value in boron-rich ICS.

Type
Research Article
Copyright
Copyright © Materials Research Society 2006

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Kimura, K. and Takeuchi, S.. in Quasicrystals: The State of the Art, 2nd ed., edited by DiVincenzo, D. P. and Steinhardt, P. J. (World Scientific, Singapore, 1999), p.325.Google Scholar
2. Kirihara, K., Nakata, T., Takata, M., Kubota, Y., Nishibori, E., Kimura, K., and Sakata, M., Phys. Rev. Lett. 85, 3468 (2000); Mater. Sci. Eng., A 294–296, 492 (2000).Google Scholar
3. Kirihara, K., Nagata, T., Kimura, K., Kato, K., Nishibori, E., Takata, M., and Sakata, M., Phys. Rev. B 68, 14205 (2003).Google Scholar
4. Pope, A. L., Tritt, T. M., Chernikov, M. A., and Feuerbacher, M., Appl. Phys. Lett. 75, 1854 (1999).Google Scholar
5. Pope, A. L., Schneidmiller, R., Kolis, J. W. and Tritt, T. M., Phys. Rev. B 63, 052202 (2001).Google Scholar
6. Maciá, E., Phys. Rev. B 64, 094206 (2001).Google Scholar
7. Akiyama, H., Honda, Y., Hashimoto, T., Edagawa, K., and Takeuchi, S., Jpn. J. Appl. Phys., 32, L1003 (1993).Google Scholar
8. Pierce, F. S., Poon, S. J., and Guo, Q., Science 261, 737 (1993).Google Scholar
9. Tamura, R., Sawada, H., Kimura, K., and Ino, H., in Proceedings of the 6th International Conference on Quasicrystals, edited by Takeuchi, S. and Fujiwara, T. (World Scientific, Singapore, 1997), p. 631.Google Scholar
10. Delahaye, J., Brison, J. P., and Berger, C., Phys. Rev. Lett. 81, 4204 (1998).Google Scholar
11. Haberkern, R., Khedhri, K., Madel, C., and Häussler, P., Mater. Sci. Eng., A 294–296, 475 (2000).Google Scholar
12. Kirihara, K. and Kimura, K., Phys. Rev. B 64, 212201 (2001).Google Scholar
13. Kirihara, K. and Kimura, K., J. Appl. Phys. 92, 979 (2002).Google Scholar
14. Nagata, T., Kirihara, K., and Kimura, K., J. Non-Cryst. Solids., (2003) in press.Google Scholar
15. Nagata, T., Kirihara, K., and Kimura, K., J. Appl. Phys. (2003) in press.Google Scholar
16. Kimura, K., Takeda, M., Fujimori, R., Tamura, R., Matsuda, H., Schmechel, R.. and Werheit, H., J. Solid State Chem., 133, 302309,(1997).Google Scholar
17. Fujimori, M., Nakata, T., Nakayama, T., Nishibori, E., Kimura, K., Takata, M., and sakata, M.. Phys. Rew. Lett Vol. 82, No. 22, 44524455(1999)Google Scholar
18. Kirihara, K., Kimura, K., Sci. Tech. of Adv. Materials, 1, 227236, (2000).Google Scholar
19. Slack, G.A., Hejna, C.I., Garbauskas, M.F. and Kasper, J.S., J. Solid State Chem., 76, 52(1998).Google Scholar
20. Geist, D., Kloss, R. and Follner, H., Acta Crystallogr. Sect. B 26, 1800(1970).Google Scholar
21. Nakayama, T., Shimizu, J., and Kimura, K.. J. Solid State Chem., 154, 1319(2000).Google Scholar
22. Kim, H.K., Nakayama, T., Shimizu, J. and Kimura, K.. 22nd International Conference on Thermoelectrics. Proceedings ICT'03, 320323 Google Scholar
23. Tamura, R., Kirihara, K., Kimura, K., and Ino, H., in Proceedings of the 5th International Conference on Quasicrystals, edited by Janot, C. and Mosseri, R. (World Scientific, Singapore, 1995), p. 539.Google Scholar
24. Haberkern, R. and Fritsch, G., in Proceedings of the 5th International Conference on Quasicrystals, edited by Janot, C. and Mosseri, R. (World Scientific, Singapore, 1995), p. 460.Google Scholar
25. Mott, N.F. and Davis, E.A., Electronic Processes in Noncrystalline Materials (Clarendon Press, Oxford, England, 1971).Google Scholar
26. Emin, D. and olstein, T., Ann. Phys. 53, 439(1969).Google Scholar
27. Wood, C. and Emin, D.: Phys. Rev. B29 (1984) 45824587.Google Scholar
28. Aselage, T.L., Emin, D., Wood, C., Mackinnon, I. and Howard, I.: Novel Refractory Semiconductors, Mater. Res. Soc. Symp. Proc., 97, ed. by Emin, D., Sselage, T.L. and Wood, C., (Mater. Res. Soc., Pittsburgh, 1987) pp.2732.Google Scholar