The aim of this article is to decrease the crystallization temperature of the tetragonal perovskite PbTiO3 nanopowders below the PbTiO3 Curie temperature (~ 500 oC). At the beginning of our study, the calcination temperature was selected based on the thermal analysis of the PbTiO3 gels, came out at 680 oC. However, detailed investigation of the thermal properties of the PbTiO3 gel revealed possibility of the formation of single tetragonal perovskite phase at lower temperatures. Pb-partitioning phenomenon (section 3.2) was investigated in detail in PbTiO3 nanopowders in order to reach good crystallization below 500 oC. Both X-Ray diffraction and transmission electron microscopy investigations showed that well crystalline pure phase PbTiO3 nanopowders have been synthesized after calcination of the PbTiO3 gel at 460 oC, which is quite close to the Curie temperature of the PbTiO3 nanoparticles. To improve crystallization of the samples prepared at 460 oC, the effects of the heat treatment parameters and Pb content on gel crystallization were investigated in detail.
Keywords: Nanopowders, PbTiO3, Sol-gel Preparation, Crystallization.