Analyis of Current Jump Phenomena in PbTiO₃-Pb(Sc_1/2Nb_1/2)O₃ Piezoelectric Ceramics

Abstract

A nonlinear piezoelectric coefficient of third-higher term for electric field, ξ_D31 was measured in x PbTiO₃ - (1-x) Pb(Sc_1/2Nb_1/2)O₃ piezoelectric ceramics. The ξ_D31 value shows minimum at the MPB composition, and its values were 1/3 to 1/4 of those in PZT ceramics. In order to analyze the current jump phenomena in these samples having relatively small ξ_D31, a 3rd nonlinear piezoelectric coefficient for mechanical stress, ζ_D31 was introduced in the theoretical formula representing the relationship between frequency and sample current in constant-voltage driving. Appling the optimized ζ_D31 value, the calculated curves well fit to the measured current curves.