Preparation and characterization of sol-gel-derived PZT thin films for microactuators

Crack-free ferroelectric thin films of lead zirconate titanate with thickness of 3 micrometers for microactuators were fabricated using Sol-Gel spin-coating onto Pt/Ti/SiO2/Si substrates. The precursor solution was prepared from lead acetate, zirconium-n-propoxide and titanium tetraisopropoxide. 2-propanol was used as the solvent. The crystalline phase as well as preferred orientation in the PZT films were investigated using x-ray diffraction analysis. The microstructure and composition of the films were studied by scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy, respectively. The well-crystallized perovskite phase and the preferred orientations in the direction of the (100) plane were obtained using the heat treatment for dry at 120 degrees C, for pyrolysis at 300 degrees C and for crystallization at 600 degrees C. The prepared films showed nanometer grains with smooth and uniform surface. The dielectric constants and loss values of these films measured at 1 kHz were approximately 1250 and 0.04, respectively, while the remnant polarization and the coercive field were 45.5 (mu) C/cm2 and 58.5 kV/cm. Our results suggest that fabrication of good structural quality PZT films of a few micrometers thick for use in micro actuators is possible.