Electrical Properties of p-Type Electronic Defects in the Protonic Conductor SrCe[sub 0.95]Eu[sub 0.05]O[sub 3−δ]

The electrical properties of were studied as a function of both oxygen partial pressure and water vapor partial pressure in the temperature range of 500-800°C, and the partial conductivities of protons, holes, and oxygen vacancies were calculated from the proposed defect model. P-type conduction was dominant in an oxidative atmosphere. It was shown that, in a wet atmosphere, is a mixed conductor of protons, holes, and oxygen ions. A conduction transition from protons to holes and/or oxygen ions was found as temperature increased. The calculated activation energy of oxygen ion transport was 0.67 eV; standard solution enthalpy of water dissolution was −164 kJ/mole, which is larger than that of The effect of dopants on the conduction mechanism is explained by a hopping mechanism. © 2003 The Electrochemical Society. All rights reserved.