Synthesis and Sintering Behavior of (Ce,Cu)-SnO_2 Nanopowders by Polymeric Precursor Methods

Nanocrystalline SnO2 powders doped with CeO2 and CuO were prepared by the polymeric precursors method. XRD, TG-DSC, TEM and SEM techniques were used to characterize the as-prepared powders and the sintered compacts. The molar ratios of citric acid to metallic elements and ethylene glycol to citric acid were 3:1 and 2:1, respectively. The precursors after burning were calcined at 550℃ in air, and spherical, well-dispersed doped SnO2 powders with an average diameter of-15nm were obtained. The relative density of 1.0%CeO2-1.5%CuO-doped SnO2 ceramics sintered at 1050℃ is over 96%; the 1.5%CuO-doped SnO2 ceramics can be densified at 1100℃. The grain size of the 1.0%CeO2-1.5%CuO-doped SnO2 ceramics densified by two-step sintering (first at 1050℃ for 15min, then cooling down to 980℃ and holding for 5h) is smaller than 800nm.