Structural, dielectric and optical properties of Cu-doped PbTiO3 ceramics prepared by sol–gel

Abstract The ceramics Pb1-xCuxTiO3 (0.00, 0.04, and 0.08) were prepared by the sol–gel technique. Their structural, dielectric and optical properties have been studied. X-ray diffraction shows that pure PbTiO3 ceramic crystallize in a tetragonal structure with a phase transition to the pseudo-cubic one after Cu doping. The temperature dependence of dielectric constant shows that the phase transition temperature decreases with increasing Cu content. Using Curie-Weiss law and its modified form, the Curie constant (C), Curie temperature (TC) and the critical exponent (γ) were calculated. The obtained values of γ pointed out the diffuse phase transformation in Cu-doped PbTiO3 samples. The optical band gap of pure and Cu-doped PbTiO3 was calculated from optical absorption spectra and was found to decrease from 3 eV to 2.814 eV as the amount of Cu increases up to 0.08.