MIXED CONDUCTIVITY IN SRCE0.95YB0.05O3 PROTONIC CONDUCTORS

The results of electrical conductivity measurements on SrCe0.95Yb0.05O 3 under controlled oxygen partial pressure and temperature are present ed. A defect model consistent with experimental results is proposed wh ich provides for p(O2)(-1/4) dependent n-type, P-O2-independent oxygen ion and p(O2)(+1/4) dependent p-type conductivity components. The ban d gap, reduction, oxidation and ion-migration energies are determined from an analysis of the data in terms of the proposed defect model. Th ese results suggest that some earlier data interpreted in terms of pro tonic conduction may require re-evaluation.