Abstract: The (Sr, Pb)TiO₃ ultrafine particles were prepared by oxalate-coprecipitation process, the thermolysisprocess of the coprecipitates (Sr, Pb)TiO(C₂O₄)₂ .4H₂O was analyzed and the crystallization temperatureand calcination comdition were defined. The averagc Primary particle size calcined at differenttemperaturcs, the crystal structurcs of sintered body and powders calcilled at different temperatures and thesintering condition of powders were also determined. The results show that the synthetic temperature of ceramic powder prepared by this process is much lower than by the conventional solid reaction process. the ceramic powder obtained is ultrafine and uniform, and the sintering temperature is lower. Exotic structure with fine grain was observed, that is, when the particle size is very small, the crystal structure is not the normal tetragonal ferroelectric structure but cubic paraelectric.

Key words: powders, copreeipitation, crystallization, strontium-lead titanate, strontium-lead titanyloxalate