Oriented aggregation of BaTiO₃ nanocrystals and large particles in the ultrasonic-assistant synthesis

BaTiO₃ particles were prepared under ultrasonic irradiation. Sphere-like and confetti-like BaTiO₃ particles composed of ca. 10 nm nanocrystals and hollow sphere particles composed of ca. 40 nm nanoparticles were obtained at different concentrations. The BaTiO₃ particles were identified as mesocrystals and the oriented aggregation, caused by ultrasonication, of 5-10 nm nanocrystals and ca. 40 nm nanoparticles, respectively, was identified.