BaTiO 3 Particle-Size Dependence of Ferroelectricity in BaTiO 3 /Polymer Composites

BaTiO 3 particle-size dependence of ferroelectricity in BaTiO 3 /polymer composites was investigated from the viewpoints of the crystal phase in BaTiO 3 powder and piezoelectric properties in BaTiO 3 /polymer composites. The crystal phase of BaTiO 3 powder was transformed from tetragonal to pseudocubic at a critical particle size of 0.1 to 0.2 µm at room temperature. The piezoelectric charge constant ( d 33 ) and hydrostatic piezoelectric constant ( d h ) were obtained through poling treatment, although their values were small in BaTiO 3 /polymer composite using the pseudocubic BaTiO 3 powder.