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.