Sol-gel derived (Ba0.5Sr0.5)TiO3 thin films and their electrical and dielectric properties

Barium strontium titanate thin films with composition (Ba0.5Sr0.5)TiO3 were prepared by a sot-gel method using hydroxide-alkoxide precursors. Reasonably well-crystallized film was obtained at a temperature as low as 500 degreesC. The leakage current characteristics and dielectric constant of the films varied with the annealing temperature due to the change in microstructure. The electrical and dielectric properties of the films showed strong dependence on the precursor solution concentration. Dielectric response of the films prepared from dilute solution is superior to that prepared from the concentrated solution. The change in electrical and dielectric characteristics of the films has been correlated to their microstructure, which revealed that the concentration change affected the grain size distribution, film porosity and morphology.