Effect of indium content on the properties of BaSn0.5Y0.5−xInxO2.75 proton conductor

BaSn0.5Y0.5−xInxO2.75 (x=0.2, 0.3 and 0.4) proton conductors were synthesized by a gel polymerization method, and the effect of indium content on the sinterability, microstructural and electrical properties were investigated. The results show that the indium doping to BaSn0.5Y0.5−xInxO2.75 can reduce the sintering temperature (1450 °C) to obtain dense pellets, and the relative densities and grain size of samples slightly increase with increasing indium content. The indium doped BaSn0.5Y0.5−xInxO2.75 leads to the decrease of lattice volume, which hampers the proton diffusion, and thus causes the decrease of the conductivity of BaSn0.5Y0.5−xInxO2.75 with increasing indium content. The maximum conductivity of BaSn0.5Y0.3In0.2O2.75 reaches 1.08×10−3 S cm at 600 °C under moist Ar atmosphere.