Oxygen exchange behaviour and electrical conductivity of polycrystalline oxide-ion conductors based on Ce1-nLanO2-0.5n

Oxide-ion conductors are used in sensors, oxygen pumps and solid oxide fuel cells. However, their range of application is limited by a low oxide-ion c onductivity in the solid electrolyte presently commercially available. The electrical conductivity and the oxygen exchange behaviour of polycrystallin e ceria-lanthania specimens with different grain boundary areas have been s tudied in an attempt to improve the grain boundary conductivity. The result s show that a large increase in the grain boundary conductivity was obtaine d. The thermodynamic properties of the oxygen nonstoichiometric defect reac tion of Ce1-nLanO2-0.5n-x solid solutions were measured by coulometric oxyg en titration. (C) 1999 Elsevier Science B.V. All rights reserved.