Electromechanical characterization of thick PT and PZT films

This work is focused on the electromechanical characterization of lead titanate and Pb(Zr_0.52Ti_0.48)O₃ thick films (30 - 100 μm) screen-printed on various substrates (alumina, silicon and glass-ceramic). Measurements of permittivity and piezoelectric constant are given at low signal and as a function of the AC electric field amplitude. Measurement of the true remanent polarization on PT films is more delicate due to the existence of an internal electric field which is different according to the type of the bottom electrode. A correct value can be achieved by extrapolation. At last the elastic stiffness and the extensional thickness coupling factor k_t are evaluated by analyzing the resonance frequency spectrum of the piezoelectric film supported by a substrate. Some reasons of inaccuracy of the results are stated.