IONIC-CONDUCTIVITY OF CALCIA, YTTRIA, AND RARE EARTH DOPED CERIUM DIOXIDE

Electrical conductivity specimens of Ce0.9Ca0.1O1.90 and Ce0.8N0.2O1.90 (N = Y, Yb, Gd, Nd, Sm, La) were prepared by a cast ceramic tape technique and by the more conventional method of isostatically pressing and sintering. The electrical conductivity of these specimens was measured in oxygen between 400°-1000°C. In this region the conduction is essentially ionic, and the temperature dependence of the electrical conductivity, σ - σ0/T exp-Ei/kT, was represented by the following second degree equation [formula omitted] where y = log σT and x = 103/T. Lower valent dopant cations with smaller ionic radii than Ce+4 exhibited a larger activation energy than cations with larger ionic radii than Ce+4. The magnitude of the electrical conductivity was not very dependent on either the type of dopant or the method of sample preparation. © 1979, The Electrochemical Society, Inc. All rights reserved.