Relaxation in polycrystalline ferroelectric ceramics upon the simultaneous impact of mechanical stresses and electric field

The motions of domain walls at low stresses are known to result in the relaxation of structural over-stresses and their balancing, while at high stresses we observe overstress increases and microcrack formation, i.e., the changing of resonance frequencies and emerging of spurious resonances of piezoelectric elements 1, 2]. In view of the above, the influence of electromechanical impacts on ceramics of compositions PZT-19 and PZT-35 are investigated in order to estimate the resonance curve changes.