Elastic Discontinuities during Switching of Ferroelectric Ceramics

Abstract

Several types of microscopic sources of elastic discontinuities are encountered in ferroelectric materials when subject to external loads. Domain switching, domain nucleation, microcracking, field induced crystallographic phase transitions, the motion of charged dislocations and frictional effects each occur under different loading conditions and generate acoustic emissions. Three compositions of lead zirconate titanate are compared for their acoustic emission patterns under electric field driving. Acoustic emission amplitudes are calculated for different source models and compared to experiment. The entire set of experiments allows a source assignment for this system. Implications for fatigue studies using the acoustic emission technique are briefly discussed.