Sintering and electrical properties of low-temperature synthesized Gd-doped ceria from polymerized precursor solutions

Low-temperature synthesis of the nano-scaled Ce0.9Gd0.1O1.95 (CGO) powder from polymer precursors and its sinterability and electrical properties were investigated. It was identified that the CGO powder was formed directly at 130degreesC from the polymerized precursor solution with initial mixing of nitrates and ethylene glycol. It is evidenced that the strong exothermic reaction during calcination of the solid intermediates derived from the polymer precursor solution can be avoided by polymerization of the precursor solution so as to obtain fine oxide powders with loosely agglomerated particle morphology. The sintered bodies of the low-temperature derived CGO powder achieve relative sintering densities of 92-99% at sintering temperatures of 1200-1500degreesC. The impedance measurements conducted in air reveal that the CGO electrolytes sintered at 1200 and 1400degreesC exhibit almost higher bulk ionic conductivities than YSZ electrolyte at the temperature below 700degreesC.