Synthesis, structural and dielectric properties of Ce-doped lead lanthanum titanate

Abstract The influence of Ce doping on the structural, dielectric and ac conductivity properties of Pb 0.79-x Ce x La 0.21 TiO 3 powders (x = 0, 0.01, 0.03, 0.05 and 0.1) was investigated. X-ray diffraction shows that all samples have the pseudo-cubic crystal structure, in which the tetragonality and cell volume decrease with increasing Ce content. The change of the dielectric constant as a function of temperature demonstrates that the phase transition temperature decreases with the increase of Ce content. Normal behavior of the phase transition from ferroelectric to paraelectric was observed for Ce-doped samples, while the undoped powders exhibit a combination of diffuse phase transition and relaxor behaviors. From electrical conductivity versus 1/T plots, we have determined the activation energy, which was found to increase with increasing Ce concentration.