The ferroelectric phase transition behavior in BaTiO3 was investigated for various annealing times, temperatures, and Ba/Ti ratios by means of a differential scanning calorimeter. Coupling these observations with powder X-ray diffraction and transmission electron microscopy allowed new insights into the barium oxide (BaO)-titanium dioxide (TiO2) phase diagram. The transition temperature was varied systematically with the Ba/Ti ratio at annealing temperatures from 1200° to 1400°C in air. The transition temperature decreased with increasing concentrations of BaO and TiO2 partial Schottky defects, and showed a discontinuous change at the phase boundaries. Beyond the solubility region, two peritectoid reactions were confirmed and revised; first around 1150°C for Ba1.054Ti0.946O2.946→Ba2TiO4+BaTiO3 and second 1250°C for BaTi2O5→Ba6Ti17O40+BaTiO3, respectively. All other regimes of the BaO-TiO2 were found to be consistent with the reported diagrams in the literature.
All Science Journal Classification (ASJC) codes
- Ceramics and Composites
- Materials Chemistry