In the La1-xBaxInO3-δ system, the compositions of x=0.1–0.3 were analyzed to consist of cubic and orthorhombic structures. The composition of x=0.4, viz., La0.6Ba0.4InO3-δ, was analyzed to be a single phase of a simple cubic. Under a dry atmosphere, La0.6Ba0.4InO3-δ exhibited a mixed conduction behavior of oxide ion and p-type electronic conductions at high oxygen partial pressures. However, in a nitrogen atmosphere, it showed pure oxide ion conduction. Proton conduction was observed in the presence of water vapor and the activation energy for proton conduction was measured as 0.84 eV.

Phase formation and conduction behavior in BaO-doped LaScO3 with the perovskite structure have been investigated. The structures of La1-x Ba x ScO3-δ were analyzed to be cubic for La0.6Ba0.4ScO3-δ and La0.5Ba0.5ScO3-δ, a mixture of cubic and orthorhombic for La0.9Ba0.1ScO3-δ, La0.8Ba0.2ScO3-δ and La0.7Ba0.3ScO3-δ, and orthorhombic for La0.95Ba0.05ScO3-δ. La1-x Ba x ScO3-δ showed a pure oxide-ion conduction below intermediate oxygen partial pressures under dry atmosphere. At high oxygen partial pressures, it exhibited mixed oxide-ion and p-type electronic conduction. In the presence of water vapor, proton conduction was observed due to the formation of protonic defects and the bulk conductivity by protons was highest in the composition of La0.5Ba0.5ScO2.75. The apparent activation energy for proton conduction was almost the same in each compound, 0.66–0.68 eV, despite the differences in crystal structure and A-site dopant concentration.

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