Microstructural and electrical characterizations of chemically prepared Ce0.8Gd0.2− x(Ag, Sr)xO1.9 (0 ≤ x ≤ 0.02)

► The influence of Sr and Ag additions to gadolinia-doped ceria was investigated. ► Sr addition enhanced grain growth and densification of gadolinia-doped ceria. ► Ag addition slowed down the densification of gadolinia-doped ceria. ► The grain conductivity is enhanced in samples containing the co-additives. ► The grain boundary blocking effect decrease gradually with increasing Sr content.