Densification and grain growth behavior study of trivalent MO1.5 (MÂ =Â Gd, Bi) doped ceria systems

Densification and microstructure for Ce0.9Gd0.1O1.95−δ and trivalent co-doped CeO2 (Ce0.9Gd0.06Bi0.04O1.95−δ) were investigated. The sinterability of co-doped nano-crystalline CeO2 was heightened compared to Gd-doped CeO2 according to the dilatometer measurements. The activation energy for densification was 745 and 419 kJ mol−1 for Gd-doped CeO2 and co-doped CeO2, respectively. The improved sintering behavior was attributed to the lower activation energy of co-doped CeO2. Investigations on the grain growth in the ceramics showed the suppressing effects of co-doped CeO2. The grain growth kinetics study indicated that the grain growth exponent, m, was 3 for Gd-doped CeO2, and 4 for co-doped CeO2, respectively.