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Thermal Conductivity and Thermoelectric Properties of Novel Rare Earth Boron-Rich Cluster Compounds; Discovery of first undoped n-type B12 icosahedral compound

Published online by Cambridge University Press:  01 February 2011

Takao Mori
Takao Mori*
Affiliation:
MORI.Takao@nims.go.jp, National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki, 305-0044, Japan, +81-29-860-4323, +81-29-851-6280
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Abstract

Novel rare earth boron icosahedral compounds are investigated as potential high temperature thermoelectric materials. REB50-type compounds and a homologous series of RE-B-C(N) compounds were synthesized and the thermal conductivity and thermoelectric properties measured. Seebeck coefficients in excess of 200 μV/K are observed at temperatures above 1000 K for the REB50-type compounds. Strikingly, n-type behavior was observed for REB22C2N and REB17CN. Up to now, non-doped B12 icosahedral compounds like boron carbide have all been p-type. The discovery of an n-type compound is extremely important in terms of the potential development of this class of compounds as viable thermoelectric materials. Low thermal conductivities of κ < 0.03 W/cm/K at room temperature was observed for these rare earth boron cluster compounds. In comparison among the homologous series in which there are rare earth and B6 octahedra layers separated by an increasing number of B12 icosahedra layers, we observe that the thermal conductivity actually increases as the number of boron cluster layers increases. We find that the rare earth B12 icosahedral cluster compounds in which RE atoms occupy voids among the clusters generally appear to have lower thermal conductivity than boron cluster compounds which do not contain RE atoms.

Keywords

thermoelectricitythermal conductivitycluster assembly
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 886: Symposium F – Materials and Technologies fore Direct Thermal-to-Electric Energy Conversion , 2005 , 0886-F11-14
Copyright
Copyright © Materials Research Society 2006

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References

REFERENCES

1. Mori, T. and Tanaka, T., J. Phys. Soc. Jpn. 68 2033 (1999).Google Scholar
2. Mori, T. and Leithe-Jasper, A., Phys. Rev. B 66 214419 (2002).Google Scholar
3. Mori, T. and Mamiya, H., Phys. Rev. B 68 214422 (2003).Google Scholar
4. Mori, T., J. Appl. Phys. 95 7204 (2004).Google Scholar
5. Emin, D., Physics Today 40 55 (1987),Google Scholar
Wood, C. and Emin, D., Phys. Rev. B 29 4582 (1984).Google Scholar
6. Werheit, H., Schmechel, R., Fueffel, V., Lundstrom, T., J. Alloys Comp. 262–263 372 (1997),Google Scholar
Nakayama, T., Shimizu, J., Kimura, K., J. Solid State Chem. 154 13 (2000).Google Scholar
7. Yagasaki, K., Notsu, S., Shimoji, Y., Nakama, T., Kaji, R., Yokoo, T., Akimitsu, J., Hedo, M., Uwatoko, Y., Physica B, 329–333 1259 (2003),Google Scholar
Takeda, M., Kurita, Y., Yokohama, K., Miura, T., MRS Symp. Proc. 793 219 (2003).Google Scholar
8. Cahill, D. G., Fischer, H. E., Watson, S. K., Pohl, R. O., Slack, G. A., Phys. Rev. B 40 3254 (1989).Google Scholar
9. Mori, T., J. Appl. Phys. 97 093703 (2005).Google Scholar
10. Mori, T. et al. , submitted.Google Scholar
11. Wood, C., Emin, D., and Gray, P. E., Phys. Rev. B 31 6811 (1985).Google Scholar
12. Slack, G. A. and Tsoukala, V., J. Appl. Phys. 76 1635 (1994).Google Scholar
13. Sales, B. C., Mandrus, D., Chakoumakos, B. C., Keppens, V., and Thompson, J. R., Phys. Rev. B 56 15081 (1997).Google Scholar
14. Nolas, G. S., Cohn, J. L., Dyck, J. S., Uher, C., and Yang, J., Phys. Rev. B 65 165201 (2002).Google Scholar
15. Mori, T. et al. , submitted.Google Scholar