Structural, morphological and electrical properties of Gd0.1Ce0.9O1.95 prepared by a citrate complexation method

A variant of the sol–gel technique known as cation complexation is used to prepare a nanocrystalline Gd0.1Ce0.9O1.95 (GDC) solid solution. A range of techniques including thermal analysis (TGA/DTA), X-ray diffraction, specific surface area determination (BET) and electron microscopy (SEM and TEM) are employed to characterise the GDC powders. GDC calcined at 500 °C is found to have an average crystallite size of 11 nm. Specific surface areas are found to be 29.7 m2 g−1 for the as-calcined powder and 57.5 m2 g−1 after ball milling at 400 rpm. Dense ceramic pellets are prepared from unmilled and ball-milled GDC powders employing different thermal treatments. Their electrical properties are studied by impedance spectroscopy. Those samples sintered at 1300 °C for 30 h (starting from ball-milled powders) exhibit the highest density (96% of theoretical density) and the highest total ionic conductivity (1.91 × 10−2 S cm−1 at 600 °C).