(1-x)Ba(Zr0.2Ti0.8)O3-x(Ba0.7Ca0.3)TiO3 Ferroelectric Thin Films Prepared from Chemical Solutions

Using chemical solution approach on Pt/Ti/SiO2/Si substrates (1 - x)Ba(Zr0.2Ti0.8)O3x(Ba0.7Ca0.3)TiO3 (BZTBCT) ferroelectric thin films were prepared for the first time. Dense and crack-free films with perovskite structure were obtained from appropriately produced precursor solution through a multiple spin-coating process in which the individual layers were pyrolyzed at different temperatures. The effects of composition and annealing temperature on the resulting structure and properties were examined. The optimized BZTBCT thin film exhibited a high dielectric constant of 2913 with a low dielectric loss of 0.06, and a high remnant polarization of 15.8 mu C/cm2 with a large coercive field of 58 kV/cm, and an effective piezoelectric coefficient d33 of 71.7 pm/V under the substrate clamping. These properties are discussed in comparison with the bulk ceramic counterpart, and the results showed that the polarization rotation and strain were restricted to a large extent in the thin films.