Preparation and Properties of Piezoelectric Lead Zirconate Titanate Thin Films for Microsensors and Microactuators by Sol-Gel Processing

PZT thin films for microsensors and microactuators were prepared from lead acetate and zirconium, titanium alkoxide solution by sol-gel processing. High-performance, crack-free, thin (3.1μm) films were acquired by multiple coating, and high-temperture annealing.PbO evaporation occurred on firing. This is caused by the lack of Pb and the structure is divided into a perovskite phase and the amorphous and/or nanocrystal regions. The existence of the amorphous and/or nanocrystal region reduces the dielectric and piezoelectric constants. Excess Pb diminishes the amorphous and/or nanocrystal region and improves the piezoelectric and ferroelectric properties.A 20mol% Pb excess PZT film has good piezoelectric properties. The dielectric constant er, the piezoelectric constant d31 and the spontaneous polarization Ps are 1800, 30.0×10-2C/m2 and 39.2×10-12C/N, respectively. These values are similar to those of bulk PZT ceramics. This PZT film will be used in the fabrication of microactuators and microsensors.