Thick piezoelectric coatings via modified sol-gel technique

A hybrid sol-gel approach is reported for the deposition of high-quality co mposite PZT films of the thickness greater than or equal to 1 mum. In this approach, the metallo-organic sol-gel precursor solution is mixed with fine piezoelectric powders and dip-coated onto Pt/Ti/SiO2/Si substrates. Differ ent organic viscous additives and deposition strategies were tried in order to deposit dense films with the properties approaching to those of bulk PZ T. Using commercial PZT powder (TRS600FG) and ultrasonic mixing during depo sition process. composite films having dielectric permittivity of similar t o 2500 and saturation polarization similar to 35 similar toC/cm(2) were obt ained. These values are intermediate between bulk ceramics and conventional sol-gel PZT films and therefore are indicative of good piezoelectric prope rties.