Nonlinear behaviors of the compositionally graded (Ba,Sr)TiO₃ thin films derived by a sol-gel process

The compositionally graded Ba_1-xSr_xTiO₃ films with a fine compositional gradient from BaTiO₃ to Ba _0.70Sr_0.30TiO₃, were fabricated on LaNiO ₃ buffered Pt-Ti-SiO₂-Si substrates, by sol-gel method. The gradient distribution of Ba and Sr species from the surface of the film to the substrate was confirmed by x-ray photoelectron spectroscopy analysis. Dielectric constant and dielectric loss showed negligible temperature dependence. The results show that factors like composition gradient, direct current bias voltage and frequency of the applied voltage can be manipulated to produce optimum dielectric properties.