Synthesis, characterization and electrical properties of piezoelectric materials by sol-gel technique

Piezoelectric materials are attractive for microelectromechanical systems (MEMS)applications, inasmuch as they have good properties capable for actuation or sensing in theseapplications. Moreover, thin film micro actuator or sensor of these materials is interestingbecause of simple design and compatible to mass production processes. With this regard, leadtitanate thin films were successfully fabricated on glass and stainless steel substrates usingsol?gel coating method. A sol was prepared by mixing lead acetate trihydrate, titanium 4-isopropoxide and glacial acetic acid in ethylene glycol. The films were obtained by dippingand dropping techniques. The obtained gel films were dried at 300 degree of a Celsius for 10minutes. The coating and drying processes were repeated many times to get desired filmthickness and the oxide thin films were finally annealed at 600 degree of a Celsius for 60minutes in air. The effects on surface morphologies of different solvent concentrations andfilm thicknesses were examined in the thin films. The obtained films were characterized byTG-DTA, XRD, SEM/EDS and spectrophotometer. In addition, dielectric properties of thefilms were investigated by using impedance.It was found that homogeneous and perovskite lead titanate thin films were prepared by a solgeltechnique under simple production conditions. Perovskite phase started to develop attemperature ranging between 400 and 500 degree of a Celsius and the pure perovskite leadtitanate phase was fully developed at 600 degree of a Celsius for 1 hour in air. The optimumsurface morphology of the film without any cracks or defects could be obtained in solutionwith maximum amount of solvent. It was determined that the value of dielectric constant anddielectric loss depended on film thickness.