Abstract
BaTiO3 particle-size dependence of ferroelectricity in BaTiO3/polymer composites was investigated from the viewpoints of the crystal phase in BaTiO3 powder and piezoelectric properties in BaTiO3/polymer composites. The crystal phase of BaTiO3 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 (d33) and hydrostatic piezoelectric constant (dh) were obtained through poling treatment, although their values were small in BaTiO3/polymer composite using the pseudocubic BaTiO3 powder.