Perovskite PbTiO3 powders were prepared by a polymerized complex technique at relatively low temperatures, viz. 400-600°C. Heating of a mixed solution of citric acid (CA), ethylene glycol (EG), and Pb and Ti ions with a molar ratio of Pb/Ti/CA/EG = 1/1/10/40 at 130°C produced a yellowish transparent polymeric gel without any precipitation, which after pyrolysis at 300°C was converted to a powder precursor for PbTiO3. We suggest, based on the results of Raman and 13C NMR spectroscopies, that a heterometallic (Pb,Ti)-CA3 chelate complex formed in a starting Pb/Ti/CA/EG solution and it was thermally stable upon polymerization at 130°C. Chemical analyses showed no PbO loss during calcination of powder precursors at 400-700°C, which led to the conclusion that a solid-state reaction between isolated PbO and TiO2 particles was not responsible for PbTiO3 formation, but PbTiO3 formed directly by thermal decomposition of the powder precursor above 400°C.
All Science Journal Classification (ASJC) codes
- 化學 (全部)
- 化學工程 (全部)