Investigation of electric displacement characteristics in sol–gel derived BaTiO 3 polycrystalline films

The ferroelectric polarization of the thin film materials obtained from the measured hysteresis loops may not be entirely derived from the actual ferro-domain switching. In order to effectively distinguish and evaluate the contribution of domain switching polarization, dielectric displacement and electric conductivity to the electric displacement of ferroelectric films, here, polycrystalline BaTiO 3 (BTO) films were grown on Si substrates by sol-gel spin-coating method. The sol-gel process and the post-annealing parameters dependent micro-crystal-structure, dielectric response, ferroelectric, especially the characteristics of electric displacement were investigated. For BTO ferroelectric films obtained under the optimized processing parameters, the measured current ( I )-time ( t ) curves as well as current ( I )-voltage ( V ) curves were suggested to evaluate the impacts of each part. The result reveals that the electric displacement of our BTO films is due to the combined contribution of the above three parts. In addition to being distinguished by I–V , the contribution of each part can also be separated by their characteristic I–t , which can also provide some important parameters in the domain switching process.