Early Stages of Crystallization of Sol−Gel-Derived Lead Zirconate Titanate Thin Films

This article reports on the early stages of nucleation and growth and texture development of the perovskite phase in PZT(52/48) seeded and unseeded sol−gel thin films. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) revealed that, in seeded films, the perovskite phase nucleates and grows at the film surface, on seed particles and at the Pt/PZT interface. In contrast, for unseeded films, nucleation and growth of the perovskite phase only occurs from the PZT/Pt interface. At low pyrolysis temperatures, the crystalline nucleation density is much higher in seeded than in unseeded films. The perovskite phase formation process is consequently accelerated by the presence of seeds. PZT thin films with 1 mol % seeds pyrolyzed at 430 °C for 40 h exhibit a dielectric permittivity of 500 and P r and E c of 6.71 μC/cm 2 and 80 kV/cm, respectively. Seeded PZT films heat-treated at low temperatures (around 400 °C) may be suitable for applications in which deposition is required onto glass, metallic, or polymeric substrates.