Hydrothermal synthesis and properties of Ce1-xGdxO2-δ solid solutions

The structure, ionic and electronic conductivities of Ce1-xGdxO2-delta (x = 0-0.30) solid solutions, prepared in a wide substitutional range for the first time hydrothermally, were investigated. The uniformly small particle size (41-68 nm) of the hydrothermally prepared materials allows sintering of the samples into highly dense ceramic pellets at 1300-1400 degreesC, a significantly lower temperature than 1600-1650 degreesC, which is required for ceria solid electrolytes prepared by solid state techniques. The solubility limit of Gd2O3 in CeO2 was determined to be over 30 mol %. The maximum conductivity, sigma(600degreesC) similar to 7.53 x 10(-3) S cm(-1) with E-a = 0.58 eV, was found at x = 0.25. (C) 2002 Editions scientifiques et medicales Elsevier SAS. All rights reserved.