Oxygen isotope exchange, water uptake and electrical conductivity of Ca-doped lanthanum zirconate

Proton concentration of La1.9Ca0.1Zr2O7 − α in H2O-O2 atmospheres has been measured by means of the method of high temperature thermogravimetry. The oxygen diffusion coefficient and the oxygen surface exchange coefficient have been measured for La1.9Ca0.1Zr2O7 − α over the temperature range of 600-900 °C using the oxygen isotope exchange method with gas phase equilibration. pO2-dependencies of the electrical conductivity have been determined in the temperature range 500-800 °C and oxygen partial pressure range of 10− 20 < pO2 < 0.21 atm in atmosphere saturated with water vapour at 25 °С (pН2О = 0.03 atm). Ionic conductivity has been divided into protonic and oxygen-ionic components. The influence of oxygen defect structure on the water uptake, oxygen diffusivity and electrical conductivity of La1.9Ca0.1Zr2O7 − α has been discussed.