Reactive Ce_0.8RE_0.2O_1.9 (RE = La, Nd, Sm, Gd, Dy, Y, Ho, Er, and Yb) Powders via Carbonate Coprecipitation. 2. Sintering

The densification behavior of nanocrystalline Ce 0.8 RE 0.2 O 1.9 (RE = La, Nd, Sm, Gd, Dy, Y, Ho, Er, and Yb) solid-solution oxides, synthesized via carbonate coprecipitation, has been investigated in air by means of constant-rate-of-heating sintering and the conventional ramp-and-holding sintering methods. Fully dense Ce 0.8 RE 0.2 O 1.9 ceramics with ultrafine microstructures (grain size ≈150−250 nm) were obtained at very low sintering temperatures of 1100−1250 °C from the powders calcined at 700 °C. The effect of calcination temperature on the sinterability of Ce 0.8 RE 0.2 O 1.9 oxides was discussed using three typical samples: Ce 0.8 La 0.2 O 1.9, Ce 0.8 Sm 0.2 O 1.9, and Ce 0.8 Yb 0.2 O 1.9 . The densification behavior of Ce 0.8 RE 0.2 O 1.9 materials was found to mainly depend on powder characteristics, that is, the rate of crystallite coarsening upon calcination, particle morphology, and the extent of agglomeration.