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SmxGdyCe1-x-yO2-δ (x+y=0.2 and x=0, 0.04, 0.08, 0.12, 0.16, 0.2) nanopowders were prepared by a copre-cipitation method. The zeta potential and sedimentation volume of Ce(OH)4 aqueous dispersions at different pH values were measured. The isoelectric point (IEP) of Ce(OH)4 suspensions is 7.0. The maximum potential value of -18.5 mV and maximum sedimentation volume of 19 ml are reached at pH=10. The evolution behaviors of the xSm(OH)3·yGd(OH)3·(1-x-y)Ce(OH)4 dried powders in the heating process was characterized by DTA/TG and XRO. The powders decompose to ceria based solid solution at a temperature below 300℃ and forms cubic fluorite structure ceria at about 650℃. The properties of SmxGdyCe1-x-yO2-δ solid solutions were characterized by XRD, TEM and BET. The lattice parameter of doped Ce02 increases linearly with increasing Sm3+ substitution (or decreasing Gd3+ substitution). The particle size of the doped ceria powders is from 5 nm to 10 nm.
The zeta potential and sedimentation volume of Ce (OH) 4 (x + y = 0.2 and x = 0, 0.04, 0.08, 0.12, 0.16, 0.2) nanopowders were prepared by a copre-cipitation method The isoelectric point (IEP) of Ce (OH) 4 suspensions is 7.0. The maximum potential value of -18.5 mV and maximum sediment volume of 19 ml are reached at pH = 10. The evolution behaviors of the xSm (OH) 3 · yGd (OH) 3 · (1-xy) Ce (OH) 4 dried powders in the heating process was characterized by DTA / TG and XRO. The powder decompose to ceria based solid solution at a temperature The properties of SmxGdyCe1-x-yO2-δ solid solutions were characterized by XRD, TEM and BET. The lattice parameter of doped Ce02 increases linearly with increasing Sm3 + substitution (or decreased Gd3 + substitution). The particle size of the doped ceria powders is from 5 nm to 10 nm.