Preparation and conductive properties of double perovskite oxides Ba3Ba1+xTa2-xO9-δ

In this work, Ba3Ba1+xTa2-xO9-delta (x = 0, 0.1, 0.3, and 0.5) double perovskite proton conductors were prepared by solid-state reaction process. Phase compositions and microstructures were characterized by X-ray diffraction and field emission scanning electron microscope techniques. valence and semi-quantitative composition of components were identified by X-ray photoelectron spectroscopy. Conductivities of Ba3Ba1+xTa2-xO9-delta were then measured under various vapor and oxygen pressures by AC impedance spectroscopy technique. Results revealed linear increase in total conductivities of Ba3Ba1+xTa2-xO9-delta oxides as a function of temperature. Ba3Ba1.3Ta1.7O8.55 exhibited the highest total conductivity of 8.41 x 10(-4) S cm(-1) under humidity and 800 degrees C. The transport numbers calculated by defect equilibria model revealed. Ba3Ba1+xTa2-xO9-delta oxides as pure proton conductors at 400-800 degrees C. Also, transport numbers of oxide ions and holes both increased with temperature. Ba3Ba1.3Ta1.7O8.55 illustrated the highest protonic transport number of 0.60 at 800 degrees C. In sum, these results suggest that Ba3Ba1+xTa2-xO9-delta oxides display excellent proton conductivity.

Automated summary

Ba3Ba1+xTa2-xO9-delta oxides demonstrate excellent proton conductivity within a certain temperature range.