Size and Temperature Dependence of Dielectric Constant of Ultrafine PbTiO₃ Particles

Using sol-gel method, we prepared ferroelectric PbTiO₃ fine particles with particle size covering the range 20-200nm; the dielectric properties of powder compact were studied in the present work. The room temperature dielectric constant increases with the decrease in particle size and reaches a maximum value at the size of about 40nm. The temperature dependence of dielectric constant involving the evolution of particle size during the measurement is discussed.