Rare earth modified Pb (Zr,Ti) O3 -Pb (Sb,Mn) O3 piezoelectric ceramics have been studied for various thermal and electrical histories. In both "freshly" poled and unpoled conditions, thermal quenching was found to increase the remnant polarization (Pr) and induced strain of hard piezoelectrics, relative to that of annealed condition. A "pinched" double-loop P-E response was found in the aged unpoled condition, whereas a single P-E loop was observed after the quenching near Curie temperature. Investigations of the effect of an applied dc bias on the P-E and ε-E responses of hard piezoelectrics were also performed. In the unpoled and quenched condition, dc bias resulted in asymmetric P-E responses and a shift of the response along the E axis. Systematic investigations revealed that internal dipolar fields and applied positive dc biases have the same effect on domain dynamics. Large internal dipolar field is essential for high power performance. A fabrication method of quenching hard piezoelectrics near the Curie temperature before poling is proposed to enhance the induced polarization and strain levels.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)