Transport properties of ceramic composites based on bismuth and indium oxides

Abstract

Solid solutions based on indium oxide In2-xZrxO3+0.5x (x = 0.005, 0.01, 0.015, 0.02, 0.025, 0.05, 0.075, 0.1) were synthesized and temperature dependences of their conductivity at 25-800 °C were investigated. It was found that In1.985Zr0.015O3.0075 solid solution possessed the highest conductivity of about 100 S/cm at 800 °C. Dense In1.985Zr0.015O3.0075 – 50 vol.% Bi2O3 ceramic composite was obtained and investigated, its microstructure was studied, and the formation of fine-grained structure with homogeneous distribution of components by volume was demonstrated. The total conductivity of composite was measured, and oxygen fluxes for composite 1.7 mm thick membrane at 750-800 °C was obtained. The oxygen flux was found to be 2.4 ×~ 10−7 mol⋅cm−2⋅s−1 at 800 °C when oxygen partial pressures on both sides of membrane was 0.21 atm/0.017 atm, while the oxygen selectivity was more than 20. This indicates thepromising of investigated composite to use as an intermediate-temperature (750800 °C) ion transport membrane for obtaining of pure oxygen from air.