Proton concentration of La1.9Ca0.1Zr2O7 - alpha in H2O-O-2 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 - alpha over the temperature range of 600-900 degrees C using the oxygen isotope exchange method with gas phase equilibration. pO(2)-dependencies of the electrical conductivity have been determined in the temperature range 500-800 degrees C and oxygen partial pressure range of 10(-20) < pO(2) < 0.21 atm in atmosphere saturated with water vapour at 25 degrees C (pH(2)O = 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 - alpha has been discussed. (C) 2017 Elsevier B.V. All rights reserved.