Thickness dependence of electrical properties of PZT films deposited on metal substrates by laser-assisted aerosol deposition

Dependence of electrical properties-dielectric, ferroelectric, and piezoelectric properties-on film thickness was studied for lead-zirconate-titanate (PZT) thick films directly deposited onto stainless-steel (SUS) substrates in actuator devices by using a carbon dioxide (CO2), laser-assisted aerosol deposition technique. Optical spectroscopic analysis data and laser irradiation experiments revealed that absorption at a given wavelength by the film increased with increasing film thickness. Dielectric constant C, remanent polarization value P,, and coercive field strength Ec of PZT films directly deposited onto a SUS-based piezoelectric actuator substrate annealed by CO2 laser irradiation at 850 degrees C improved with increasing film thickness, and for films thicker than 25 mu m, epsilon > 800, P-r > 40 mu C/cm(2), and E-c < 45 kV/cm. In contrast, the displacement of the SUS-based actuator with the laser-annealed PZT thick film decreased with increasing film thickness.