It was noted that this mixed conductor exhibited anomalous electrical properties which depended upon the O partial pressure and the CeO2 concentration. The surface reaction rates and O tracer diffusion coefficients of samples having various CeO2 concentrations were measured by means of secondary ion mass analysis. The Ce concentration-dependence of the O tracer diffusion coefficient in air corresponded to that of the total conductivity; in which the ionic conductivity was dominant. The surface exchange coefficient had a higher value in the region of 20 to 60mol%CeO2 samples, as compared with other compositions. Samples which included this region of CeO2 concentration exhibited high electronic conduction under reducing conditions. The ionic and electronic conductivities were suggested to affect the O tracer diffusion coefficient and the surface exchange coefficient, respectively.

Oxygen Transport Properties in ZrO2-CeO2-Y2O3 by SIMS Analysis. H.Naito, N.Sakai, T.Otake, H.Yugami, H.Yokokawa: Solid State Ionics, 2000, 135[1-4], 669-73