This work reports the electrical conductivity of CeO2-10 mol% Gd2O3 co-doped with x mol% Sm2O3 (0 < x < 2). The lattice parameter and the average grain size were insensitive to co-doping. However, the addition up to 1.0 mol% of co-dopant increased the grain electrical conductivity and above this level a decrease was detected in spite of the lattice parameters and average grain size remained constant. The grain boundary electrical conductivity increased systematically with the increase of co-doping. This behavior has been associated to the influence of co-doping in the space charge layer.
ceria; electrical conductivity; co-doping
