A stable solution chemistry and a consistent thermal processing route have been developed to produce multi-layer sol-gel lead zirconate titanate (PZT) piezoelectric coatings of high electrical quality. Up to 5 mu m thick fully perovskite and piezoelectrically active crack-free coatings with permittivity of 1100-1300 and loss tangents of 1-2% can be produced with careful attention to the choice of titanium and zirconium alkoxide precursors, the choice of solvent, the method of solution preparation, and the thermal processing schedule. The films were deposited on platinized silicon, spinning for 30 seconds at 3000 rpm. Individual layers were dried on a hot plate at 250 degrees C for 30 seconds, fired on a second hot plate at 400 degrees C for 15-60 seconds and annealed in a box furnace at 650 degrees C for 2 minutes. Applications of the films are directed toward piezoelectric transformers, surface acoustic wave devices, and cantilever structures.

The dielectric and piezoelectric response of sol gel based films and composite coatings is affected by the choice of process, gel composition, thermal cycle, processing atmosphere and poling conditions. Important general factors for thin films are the crystallization kinetics and the effects of residual carbon, while a new dielectric technique allows poling methods to be evaluated.