Preparation of Ce0.8Gd0.2O1.9 Powder Using CeO2 Powder and Gd Precipitation and Effect of CoO doping on Sintering

Ce0.8Gd0.2O1.9 (GDC20) powder was prepared from a mixture of submicron-sized CeO2 powder and Gd precipitates using ammonium carbonate ((NH4)(2)CO3) as a precipitant. The mixture was calcined at 700 degrees C for 4 h followed by ball-milling that resulted in the GDC powder with an average particle size of 0.46 mu m. The powder had a very uniform particle size distribution with particle sizes ranging from 0.3 mu m to 1 mu m. Sintering of undoped GDC samples did not show a relative density of 99.2% until the temperature was increased to 1500 degrees C, whereas GDC samples doped with 5 mol% CoO exhibited a significant densification at lower temperature reaching a relative density of 97.6% at 1100 degrees C and of 98.8% at 1200 degrees C.