Hostname: page-component-78c5997874-4rdpn Total loading time: 0 Render date: 2024-11-09T08:54:00.550Z Has data issue: false hasContentIssue false

Electrical Conductivity of Pure and Doped Nanocrystalline Cerium Oxide

Published online by Cambridge University Press:  10 February 2011

E. B. Lavik
Affiliation:
Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
Y.-M. Chiang
Affiliation:
Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
Get access

Abstract

We have previously shown that dense nanocrystalline CeO2−x of approximately 10 nm grain size exhibits enhanced electrical conductivity and an enthalpy of reduction that is more than 2.4 eV lower than that for conventional ceria [1, 2]. These effects were attributed to preferential interface reduction. In this work, we investigated the relationship between interfacial area, heat treatment conditions, and conductivity by varying the grain size of dense samples through annealing at various temperatures. It is shown that the conductivity does not scale in direct proportion to interfacial area. Moderate temperature (700 °C) anneals which change the grain size by only a few nanometers reduce the conductivity by three orders of magnitude. It is suggested that atomistic relaxation occurs at the interfaces, and eliminates many low energy defect sites.

Type
Research Article
Copyright
Copyright © Materials Research Society 1997

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. Lavik, E. B., Chiang, Y.-M., Kosacki, I., and Tuller, H. L., Mat. Res. Symp. Proc. 400, Pittsburgh, PA, 1996, pp. 359364.Google Scholar
2. Chiang, Y. -M., Lavik, E. B., Kosacki, I., Tuller, H. L., and Ying, J. Y., Appl. Phys. Lett., 69 185 (1996).Google Scholar
3. Tschoepe, A. and Ying, J. Y., p. 781 in Nanophase Materials. Hadjipanayis, G. C and Siegel, R. W., eds., Kluwer Academic Publishers, Netherlands, 1994.Google Scholar
4. Liu, W., and Flytzani-Stephanopoulos, M., submitted to J. of Catalysis.Google Scholar
5. Tschoepe, A., Liu, W., Flytzani-Stephanopoulos, M., and Ying, J. Y., J. of Catalysis, 157 42 (1995).Google Scholar
6. Gerhardt, R. and Nowick, A. S., J. Am. Ceram. Soc, 69 641 (1986).Google Scholar
7. Gerhardt, R., Nowick, A. S., Mochel, M. E., and Dumler, I., J. Am. Ceram. Soc, 69 647 (1986).Google Scholar
8. Aoki, M., Chiang, Y. -M., Kosacki, I., Lee, L. J. -R., Tuller, H., and Liu, Y., J. Am. Ceram. Soc, 79 1169(1996).Google Scholar
9. Terwilliger, C. D. and Chiang, Y. -M., Acta Metall. Mater., 43 319 (1995).Google Scholar
10. Chiang, Y. -M., Lavik, E.B., and Blom, D. A., to appear in Nanostructured Materials, Vol. 9, 1997.Google Scholar
11. Tuller, H. L. and Nowick, A. S., J. Phys. Chem. Solids, 38 859 (1977).Google Scholar
12. Tuller, H. L. and Nowick, A. S., J. Electrochem. Soc, 126, 209 (1979).Google Scholar
13. Tuller, H. L. and Nowick, A. S., J. Electrochem. Soc, 122, 255 (1975).Google Scholar
14. Sayle, T. X. T. et al. , Surf. Sci., 316, 329 (1994).Google Scholar