The crystallographic symmetries, chemical compositions, electrical conductivities, and electrochemical behaviors of the oxides BaFeO_(3-y)(A), Ba_(0.9)La_(0.1)FeO_(3-y)(B) and Ba_(0.8)Sr_(0.1)La_(0.1)FeO_(3-y)(C) having perovskite structures were inve...
The crystallographic symmetries, chemical compositions, electrical conductivities, and electrochemical behaviors of the oxides BaFeO_(3-y)(A), Ba_(0.9)La_(0.1)FeO_(3-y)(B) and Ba_(0.8)Sr_(0.1)La_(0.1)FeO_(3-y)(C) having perovskite structures were investigated. X-ray powder diffraction assigns all the samples to cubic symmetries. At the constant temperature of 323K, the electrical conductivities(logσ) of B-1 (-0.02(Ωㆍcm)^(-1)) and C-1 (-0.58(Ωㆍcm)^(-1)) were much larger than that of A-1 (-4.87(Ωㆍcm)^(-1)). Cyclic Voltammograms of B-1 indicates that there exists a plateau in the range of E=0.4~0.5V, which confirms the coexistence of Fe^(3+) and Fe^(1+) ions and the following anodic oxidation process : (Fe^(3+)_(surface) → (Fe^(4+)_(surface) + e .