Haile, Sossina M. and West, David L. and Campbell, John (1998) The role of microstructure and processing on the proton conducting properties of gadolinium-doped barium cerate. Journal of Materials Research, 13 (6). pp. 1576-1595. ISSN 0884-2914 http://resolver.caltech.edu/CaltechAUTHORS:HAIjmr98
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The influence of grain boundary conductivity and microstructure on the electrical properties of BaCe0.85Gd0.15O3-<>d have been examined. Grain sizes were varied by sintering at various temperatures. Impedance data were analyzed using the brick layer model, and some new consequences of this model are presented. The specific grain boundary conductivity exhibits an activation energy of ~0.7eV, and for similar processing routes, is independent of grain size. An isotope effect was observed, indicating that protons (or deuterons) are the mobile species. TEM investigations showed the intergranular regions to be free of any glassy phase that could account for the differences in bulk and grain boundary properties. Single crystal fibers, grown by a modified float zone process, were notably barium deficient, and exhibited a low conductivity, comparable to that of polycrystalline Ba0.96Ce0.85Gd0.15O3-δ.
|Additional Information:||© 1998 Materials Research Society (Received 19 August 1997; accepted 12 January 1998) The authors thank Dr. Paul Carpenter (California Institute of Technology) and Dan Frech (University of Washington) for assistance with scanning electron microscopy and transmission electron microscopy, respectively. We also thank Geoff Staneff, who performed grain size measurements. Dr. Robert Feigelson (Stanford University) has kindly provided access to single crystal growth facilities. J.C. is grateful to Darryl Shima (formerly of the University of Washington) for guidance with experimental techniques. Funding of this work has been provided by the National Science Foundation through a National Young Investigator Award, and by the Electric Power Research Institute.|
|Subject Keywords:||ceramics; electrical properties|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Archive Administrator|
|Deposited On:||17 Oct 2006|
|Last Modified:||26 Dec 2012 09:05|
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