PREPARATION OF PZT THIN-FILMS BY SOL-GEL PROCESS AND PROPERTIES

Thin films of piezoelectric lead zirconate titanate (PZT) were prepared by the dip-coating method in the sol-gel process. Lead acetate, zirconylnitrate and titanium tetra-n-butoxide were used as raw materials. Water, acetic acid and tri-ethylene glycol were used as solvents. A thin film was prepared by dipping a substrate having a thin layer of ITO electrode on a silica glass plate. Thin films having single-phased PZT were obtained by heat-treatment at 600-degrees-C for 2 h in air. The film thickness was 0.155-mu-m per dipping, and PZT films 1-3-mu-m thick were prepared by multiple deposition technique. Au thin layer by PVD method was used as upper electrodes. The dielectric constants and losses for the composition ratio (PZ/PT) of 53/47 were 1380 and 0.03, respectively by heat-treatment at 750-degrees-C for 2 h. The spontaneous polarization, the remanent polarization and the coercive field were 21-mu-C/cm2, 11-mu-C/cm2 and 34 kV/cm, respectively. These films prepared by the sol-gel process were shown to have more excellent dielectric properties and transparency than the conventional powder method.