Electron microscopic observation of the microstructure of sol-gel derived PZT thin film

Lead zirconate titanate (PZT) thin films were fabricated by a three-step heat-treatment process, which involves the addition of 20 mol% excess Pb to the starting solution and spin coating onto Pt/Ti/SiO₂/Si substrate. Microstructure of the PZT film has been investigated using analytical and high-resolution electron microscopy. The film is crystallized in the perovskite phase with columnar grains and few pores on the order of nanometer are formed just below the layer interfaces. It is found that the presence of 1-2 nm layers of Pb-rich amorphous at grain boundaries. At the interface between PZT/Pt, second phases, such as PbO or Pt_xPb does not exist. It is considered that the (111) and (100) preferred orientation in the PZT film was not promoted by the Pt_xPb and PbO phase.