The effect of the defect structure upon the electrical conductivity of Eu-doped SrCeO3 was studied in a reducing range of PH2, PH2O, PO2. A defect model was confirmed by a computational simulation of electrical conductivity data and Brouwer-type defect equilibria. At higher temperatures, part of the conductivity was due to O vacancies and electrons. At low temperatures, protonic conduction predominated. The measured total conductivity was proportional to PO2-1/8 at 650 to 750C, and to PO2-1/6 at 800C, in wet atmospheres because of a transition from ionic- to electronic-dominant conduction. The results agreed with a defect model which was based upon the equilibrium equation for the valence change in Eu ions from trivalent to divalent.

Defect Structure and n-Type Electrical Properties of SrCe0.95Eu0.05O3–δ. S.J.Song, E.D.Wachsman, S.E.Dorris, U.Balachandran: Journal of the Electrochemical Society, 2003, 150[11], A1484-90