Abstract
Nanopowders of ceria doped with 20 at.% of rare-earth cations (Sm, Gd, and Y) have been obtained via thermal decomposition of carbonate precursors precipitated from mixed nitrate solutions with ammonium carbonate as the precipitant. Characterizations of the powders were achieved by elemental analysis, DTA/TG , XRD, BET, and FESEM. The fluorite-structured oxide solid solutions were formed directly during calcination, without any second phases detected with XRD.The coarsening rate of the oxide crystallites during calcination various with the radius of dopant cations, being the highest for Sm-doped powder and the lowest for the Y-doped one. Sintering studies indicate that these carbonate-derived oxide solid solutions are of high reactivity, and fully densified ceramics have also been obtained by isothermal sintering at a very low temperature of 1050 degree C for 4 h..
