Piezoelectric properties of PLZT ceramics at different remanent polarization levels

The piezoelectric, electromechanical, and dielectric properties of lead lanthanum zirconate titanate (PLZT) ceramics at different remanent polarization levels were studied for acoustic imaging applications. The remanent polarizations at different levels were achieved by applying electric switching pulses with different widths. The piezoelectric coefficient obtained by direct and converse effects decreased with the remanent polarization, but the relations were not linear. The electromechanical coupling factor also decreased with the remanent polarization and the mechanical quality factor was not basically affected by remanent polarization. The dielectric properties varied in different polarization states, but they had different behaviors for different crystal structures of samples. The aging effect was researched in several partially polarized states and in the completely polarized state. No apparent difference in aging rates was observed