Effects of annealing processes of Ba0.9Ca0.1TiO3 films on their microstructures, ferroelectric and dielectric properties

Lead-free films of Ba0.9Ca0.1TiO3 (BCT) films were prepared on the Pt/Ti/SiO2/Si substrate via the sol–gel method under three different annealing processes. The films prepared under the three annealing processes contain only BCT phase and phase from the substrate without impurity phases. Under the complete annealing process (CAP), the BCT films possess best crystallinity, the typical grain and dense structures, the most flat surface, uniform film thicknesses. The root-mean-square roughness of BCT film prepared under CAP is 1.94 nm. The film prepared under CAP possesses the largest remanent polarization and dielectric constant, smallest coercive field and dielectric loss. These results indicate that, among the three annealing processes, CAP is the best for preparing films of BCT with best ferroelectric and dielectric properties.