Ultrasonic assisted synthesis of BaTiO₃ nanoparticles at 25 °C and atmospheric pressure

Barium titanate (BaTiO₃) nanoparticles were successfully synthesized via a sonochemical method (25 kHz) at a constant temperature of 25 °C and atmospheric pressure without a calcination step. Barium hydroxide Ba(OH)₂ and diisopropoxytitanium bis(acetylacetonate) (C₁₂H₂₈O₆Ti) were used as the starting materials. The effects of the concentration of NaOH used and ultrasonic reaction time were investigated. The phase composition, functional groups and morphology of synthesized powders were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Fourier transform Raman spectroscopy (FT-Raman) and transmission electron microscopy (TEM). The XRD and FT-Raman results revealed the cubic structure of BaTiO₃. The optimal NaOH concentration and ultrasonic reaction time for producing a narrow particle size distribution and the bowl-like structure of BaTiO₃ nanoparticles were 10 M and 1 h, respectively. TEM imagery showed their morphology as a monodispersed bowl-like structure with a size of 54.90 ± 18.18 nm. After longer ultrasonic contact times, the bowl-like structure tended to fracture forming irregularly shaped nano-sized BaTiO₃ particles.