Microstructure and Grain-boundary Effect on Electrical Properties of Gadolinium-doped Ceria

Abstract

The microstructural evolution and grain-boundary influence on electrical properties of Ce0.90Gd0.10O1.95 were studied. the nanoscale powders synthesized from a semibatch reactor exhibited 50% green density and 92% sintering density at 1200°C (∼200°C lower than previous studies). Impedance spectra as a function of temperature and grain size were analyzed. the Ce0.90Gd0.10O1.95 with finest grain size possessed highest overall grain-boundary resistance; this contribution was eliminated at temperatures >600°C, regardless of grain size. the grain conductivity was independent of grain size and was dependent on temperature with two distinct regimes, indicative of the presence of Gd′Ce−Vo∘∘ complexes that dissociated at a critical temperature of ∼580°C. the activation energy for complex dissociation was ∼0.1 eV; the value for the grain-boundary was ∼1.2eV, which was size independent.

Department(s)

Materials Science and Engineering

Keywords and Phrases

Cerium/Cerium Compounds; Grain Boundaries; Conductivity; Microstructure

International Standard Serial Number (ISSN)

0002-7820; 1551-2916

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2004 Wiley-Blackwell, All rights reserved.

Publication Date

01 Dec 2004

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