Particle-size dependence of crystal structure of BaTiO3 powder

The particle size dependence of BaTiO3 powder was investigated from the viewpoint of the crystal phase. The crystal phase of BaTiO3 powder was transformed from tetragonal to cubic at a critical particle size of 0.1 mum at room temperature. With decreasing particle size, the Ba ions in the BaTiO3 structure were absent at the surface, and these disordered surface areas increased in small-particle-size BaTiO3 powders and exhibited particle-size dependence.