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High-purity-doped ceria compounds Ce_1-x RE _x O_2-δ (RE = Sm, Gd; 0 ≤ x ≤ 0.30) were synthesized by the Pechini method at 400 °C. Nanostructured products of crystallite size 5–11 nm were obtained, presenting a single fluorite cubic phase and high surface area values in the range of 75–110 m²g⁻¹. Dense ceramic products with a relative density of 96–98 % resulted after sintering at 1450 °C. Impedance spectroscopy was used to study the conductivity of these compounds in the temperature range of 200–750 °C. Between 600 and 730 °C, the compounds with x = 0.15, 0.20 show conductivities on the order of 10⁻¹ Scm⁻¹, with activation energies between 0.9 and 1.1 eV. Surface areas and conductivity values were found to be comparable with the highest values reported in the literature for similar compounds.