Electrical properties of the fluorine-doped Ba 2In 2O 5

Abstract

The novel brownmillerite-type oxyfluorides Ba 2 - 0.5xIn 2O 5 - xF x (x ≤ 0.30) were synthesized by solid state method. Their structure, microstructure, electrical properties and thermal stability have been investigated. These phases are capable of dissociative dissolution of water and can exhibit proton transport. Electrical conductivity and transport numbers were measured with varying T and pO 2 in dry (pH 2O = 4.5 10 - 4 atm) and wet (pH 2O = 1.42 10 - 2 atm) atmospheres. The F --transport numbers increase with increasing x and the temperature, although at the temperature T < 600 °C the F --transport numbers are negligible. The concentration dependencies of the partial conductivities were discussed. It was established that small F --concentrations can improve the oxide-ion and the proton conductivities. © 2011 Elsevier B.V.