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Enhanced Electrical Conductivity and Nonstoichiometry in Nanocrystalline CeO2-x

Published online by Cambridge University Press:  15 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
I. Kosacki
Affiliation:
Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
H.L. Tuller
Affiliation:
Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
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Abstract

Dense nanocrystalline CeO2-x. of ∼10 nm grain size exhibits enhanced, PO2-dependent electronic conductivity indicative of intrinsic nonstoichiometric behavior under conditions where coarse-grained counterparts are extrinsic. The enthalpy of reduction is lowered by over 2.4 eV per oxygen vacancy. The nanocrystals also exhibit greatly reduced grain boundary resistance, attributed to grain-size-dependent segregation. We propose that interface doping by selected low energy defect sites dominates the defect and transport properties of nanocrystalline ceria, and possibly other nanocrystalline compounds.

Type
Research Article
Copyright
Copyright © Materials Research Society 1996

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