Laser Irradiation Effect of Film Thickness on the Properties of Aerosol Deposition-Derived PZT Films on Metal Substrate

Film thickness dependence of ferroelectric and/or piezoelectric properties for PZT films directly deposited onto stainless-steel (SUS) substrates in actuator devices by CO₂ laser-assisted aerosol deposition was investigated. Analysis of the optical spectroscopic data and experimental results of laser irradiation revealed that absorption of an CO₂ laser wavelength by the film increased with increasing the film thickness. Dielectric constant, remanent polarization, and coercive field values of the film irradiated by the CO₂ laser at an annealing temperature of 850degC increased with increasing the film thickness region of 5 to 30 mum. The dielectric constant, remanent polarization, and the coercive field values of the PZT film, which irradiated by the laser, with a thickness of over 25 mum directly deposited onto the SUS substrate were over 800 and 40 muC/cm² and under 45 kV/cm, respectively. Whereas, a displacement as the piezoelectric property of a SUS-based actuator with the PZT film irradiated by the laser decreased with increasing the film thickness. Finally, the reason and some countermeasure of deterioration of the ferroelectric and/or piezoelectric properties and the displacement for the SUS-based actuators with the PZT film irradiated by the laser are discussed.