Title

Impedance Studies of Diffusion Phenomena and Ionic and Electronic Conductivity of Cerium Oxide

Abstract

In this study, the electrical conductivity of undoped cerium oxide is evaluated using impedance spectroscopy. We have observed a new phenomenon, which is not related to electrode response but probably to diffusion processes in the grain boundary. An equivalent circuit has been constructed based on the observation, and the electronic bulk, ionic grain, and ionic grain boundary conductivities are calculated. Evaluation of fitting results to the proposed equivalent circuit suggests that diffusion-related phenomena are caused by blocking effects in the grain boundaries due to impurity segregation. Investigation of the grain boundary composition by energy dispersive X-ray spectroscopy shows that it contains detectable amounts of impurities in comparison to the grain, which supports the suitability of the proposed equivalent circuit.

Department(s)

Materials Science and Engineering

Sponsor(s)

United States. Department of Energy

Keywords and Phrases

Constant Phase Elements; Mixed Conductors; Undoped Cerium Oxide CeOx

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2005 the Electrochemical Society (ECS), All rights reserved.


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