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Electrical Properties and Defect Structure in The Sr-Fe-Co-O System

Published online by Cambridge University Press:  10 February 2011

B. Ma ,
C.-C. Chao ,
J.-H. Park ,
C. U. Segret  and
U. Balachandran
B. Ma
Affiliation:
Energy Technology Division, Argonne National Laboratory, Argonne, IL 60439 USA Department of Physics, Illinois Institute of Technology, Chicago, IL 60616 USA
C.-C. Chao
Affiliation:
Energy Technology Division, Argonne National Laboratory, Argonne, IL 60439 USA
J.-H. Park
Affiliation:
Energy Technology Division, Argonne National Laboratory, Argonne, IL 60439 USA
C. U. Segret
Affiliation:
Department of Physics, Illinois Institute of Technology, Chicago, IL 60616 USA
U. Balachandran
Affiliation:
Energy Technology Division, Argonne National Laboratory, Argonne, IL 60439 USA
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Abstract

The ceramic Sr-Fe-Co-O has potential use as a membrane in gas separation. This material exhibits high conductivity of both electrons and oxygen ions. It allows oxygen to penetrate at high flux rates without other gas components. Electrical properties are essential to understanding the oxygen transport mechanism and defect structure of this material. By using a gas-tight electrochemical cell with flowing air as the reference environment, we were able to achieve an oxygen partial pressure (P02) as low as 10−16 atm. Total and ionic conductivities of Sr-Fe-Co-O have been studied as a function of P02 at elevated temperature. In air, both total and ionic conductivities increase with temperature, while the ionic transference number is almost independent of temperature, with a value of ≈0.4. Experimental results show that ionic conductivity decreases with decreasing P02 at high P02 (≥10−6 atm). This suggests that interstitial oxygen ions and electron holes are the dominant charge carriers. At 800°C in air, total conductivity and ionic conductivity are 17 and 7 S/cm, respectively. Defect dynamics in this system can be understood by means of the trivalence-to-divalence transition of Fe ions when P02 is reduced. By using the conductivity results, we estimated oxygen penneation through a ceramic membrane made of this material. The calculated oxygen permeability agrees with the experimental value obtained directly from an operating methane conversion reactor.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 411: Symposium T – Electricaly-Based Microstructural Characterization , 1995 , 163
Copyright
Copyright © Materials Research Society 1996

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References

REFERENCES

1. Balachandran, U., Morissette, S. L., Dusek, J. T., Mieville, R. L., Poeppel, R. B., Kleefisch, M. S., Pei, S., Kobylinski, T. P., and Udovich, C. A., Proc. Coal Liquefaction and Gas Conversion Contractors Review Conf., edited by Rogers, S. et al., Vol.1, pp. 138–160, U.S. Dept. of Energy, Pittsburgh Energy Technology Center, Pittsburgh, PA (1993).Google Scholar
2. Mazanec, T. J., Cable, T. L., and Frye, J. G. Jr., Solid State Ionics, 111, 53 (1992).Google Scholar
3. Balachandran, U., Dusek, J. T., Sweeney, S. M., Mieville, R. L., Maiya, P. S., Kleefisch, M. S., Pei, S., Kobylinski, T. P., and Bose, A. C., presented at 3rd Int. Conf. on Inorganic Membranes, July 10–14, Worcester, MA (1994).Google Scholar
4. Pei, S., Kleefisch, M. S., Kobylinski, T. P., Faber, J., Udovich, C. A., Zhang-McCoy, V., Dabrowski, B., Balachandran, U., Mieville, R. L., and Poeppel, R. B., Catalysis Lett., 30, 201 (1995).Google Scholar
5. Balachandran, U., Dusek, J. T., Sweeney, S. M., Poeppel, R. B., Mieville, R. L., Maiya, P. S., Kleefisch, M. S., Pei, S., Kobylinski, T. P., Udovich, C. A., and Bose, A. C., Am. Ceram. Soc. Bull., 74, 71 (1995).Google Scholar
6. Cable, T. L., European Patent EP 0438 902 A2 (31 July 1991).Google Scholar
7. Anderson, H. U., Chen, C. C., Tai, L. W., and Nasrallah, M. M., Proc. 2nd Int. Symp. On Ionic and Mixed Conduction Ceramics, edited by Ramanarayaman, T. A., Worrell, W. L. and Tuller, H. L., pp. 376–387, The Electrochem. Soc. (1994).Google Scholar
8. Park, J.-H., Physica B, 150, 80 (1988).Google Scholar
9. Ma, B., Park, J.-H., Segre, C. U., and Balachandran, U., to be published in Proc. Materials Research Soc. Spring Meeting, April 17–21, San Francisco, CA (1995).Google Scholar
10. Kroger, F. A., “The Chemistry of Imperfect Crystals,” North-Holland Publishing Co., Amsterdam (1964).Google Scholar
11. Brouwer, G., Philips Res. Rep., 9, 366 (1954).Google Scholar
12. Ma, B., Balachandran, U., Park, J.-H., and Segre, C. U., to be published in J. of Electrochem. Soc. Google Scholar
13. Tuller, H. L., “Mixed Conduction in Nonstoichiometric Oxides,”in Nonstoichiometric Oxides, Materials Science Series, Sorensen, O. T., Ed., pp. 271, Academic Press, New York (1981).Google Scholar
14. Kruidhof, H., Bouwmeester, H. J. M., Doorn, R. H. E., and Burggraf, A. J., Solid State Ionics, 63, 816 (1993).Google Scholar