Abstract
Spherical fine particles of SrTiO3 were prepared by ultrasonic spray pyrolysis of a methanol solutoin containing Sr and Ti iso-propoxides. The microstructure and composition of particles were studied by TEM and SEM. TEM observation revealed that the particles prepared at 1200°C have a hollow around the center of the particle and consist of small primary particles of 0.02-0.05μm. This primary particle size was comparable to both the particle size calculated from the specific surface area and crystallite size derived from XRD line broadening. While the particles prepared at 600°C contained some unreacted alkoxide and gave a broad XRD pattern and had no distinct particle shape in TEM photograph, particles calcined at 1000°C consisted of well developed crystalline primary particle of 0.02-0.05μm.
The mechanism of particle formation and microstructure development were discussed based on partial hydrolysis and complex alkoxide polymer formation.
