Investigation of Phase Transition for BaTiO _<b>3</b> Nanoparticles Using a Laboratory-Grade High-Temperature X-ray Diffractometer

BaTiO₃ (BTO) nanoparticles with a size of 12 nm were prepared, and their phase transition behavior was investigated using a laboratory-grade high-temperature X-ray diffractometer. The {111}, {200}, and {220} reflections were measured carefully, and Full Width at Half Maximum (fwhm) of these reflections was estimated. As a result, the fwhm of the {200} reflections decreased with increasing temperature and remained constant above the phase transition temperature. In contrast, the fwhm of the {111} reflections remained unchanged over the temperature range from room temperature to 600 °C. These results indicate that the structure of BTO nanoparticles with a size of 12 nm transforms from tetragonal to cubic at the phase transition temperature, and the phase transition of BTO nanoparticles can be detected using a laboratory-grade high-temperature X-ray diffraction apparatus by comparing the variation of fwhm with temperature.