Preparation of transparent ferroelectric Pb0.92La0.08Ti0.96O3 thick films on ITO-coated glass substrates by a sol–gel route

Pb0.92La0.08Ti0.96O3 films with thickness between 580 nm and 1830 nm were deposited on ITO-coated glass substrates using a sol–gel process under a relative low temperature of 580 °C. The films are crystallized well and of pure perovskite polycrystalline structure, and the surface of the films was smooth and condense. With the increase of the film thickness, the grain size and dielectric constants of the films increase. The dielectric constant-voltage curves are symmetric about a zero-bias axis and showed the hysteresis for all the films. In addition, the coercive field Ec decreases with the film thickness. All the films are transparent and the absorption edges were found to shift to longer wavelength with increasing thickness of the films. The refractive index (n) and extinction coefficient (k) of 1830 nm thick film are 2.39 and 0.009, respectively, at 633 nm wavelength.