Fabrication of PZT BY sol-gel method

The sol-gel method was used to prepare the high purity lead zirconate titanate Pb(Zr,Ti)O₃ (PZT) piezoelectric ceramic powders. To determine the optimum fabrication process, the influence of calcined conditions and sintering conditions on the characteristics of PZT bulk was studied. After calcined at 900°C for 4hr, and then sintered at 1100°C for 2hr, the density of the bulk ceramics nearly equal to 8g/cm³. The polycrystalline PZT thin film was prepared by using spin coating method. The PZT thin films with lower gel concentration of 0.2M were used, and deposited on Al/Si₃N₄/Si(100) substrate. After drying at 150°C, pre-baking at 350°C and sintering at 600°C~700°C, the amorphous PZT thin films have been changed to perovskite-type crystal structure. The influence of gel solutions concentration and heating conditions on the morphology of PZT thin films were discussed. The cracking problem was alleviated by employing lower gel concentration of 0.2 M with a drying at 150°C for 5 min and a pre-baking at 350°C for 10 min, and then sintering at 700°C for 30 min with a heating rate 50°C/min. The values of the remanent polarization (Pr) and coercive field (Ec) are 11.39μc/cm² and 84.52 kV/cm, respectively.