Crystallographic parameters of spherulitic structures in ferroelectric film

The symmetry and structure of ferroelectric films determine most of their properties. Nonlinear optical technique of second harmonic generation (SHG) is widely accepted for remote and fast qualitative characterization of ferroelectric films. In this article, we develop a method for quantitative characterization of the local symmetry and structure of PZT thin films. Depending on the annealing time of pyrochlore phase two types of structure have been obtained: continuous perovskite polycrystalline film consisting of truncated spherulites and isolated spherulites embedded into pyrochlore matrix. The method is based on the SHG azimuthal dependences measurements followed by fitting procedure and gives the ratio of monoclinic to tetragonal phases as well as the fraction of differently oriented crystallographic faces of both of these phases.