Preparation of Ce0.8Gd0.2O1.9 powder by milling of CeO2 slurry and oxalate precipitation

Abstract

Ce0.8Gd0.2O1.9(GDC20) powder was synthesized by milling of CeO2 slurry and Gd oxalate precipitation. The mixture of CeO2 powder and Gd precipitates calcined at 600°C for 2 h showed the particle size distribution similar to that of CeO2 powder, which had been milled during the synthesis process. Attrition milling of the calcined powder with an average particle size of 0.36 μm for 2 h resulted in a decrease in the particle size to 0.24 μm. Although the milled powder consisted of small particles(<1 μm), a small amount of fine platy Gd2O3 particles, which had been survived in the milling process, was observed. Sintering of the powder compacts for 4 h showed relative densities of 80.7% at 1300°C and 97% at 1400°C, respectively. Densification was found to almost complete at 1500°C, resulting in a dense and homogeneous microstructure with a relative density of 99.5%.