Microstructural Evolution under Polarization Switching of Ferroelectric Tin-modified Lead Zirconate Titanate Ceramics

Abstract

Electric fatigue properties of ferroelectric niobium-doped tin-modified lead zirconate titanate (PNZST) ceramics were investigated using polarization-electric field (P–E) measurements, and the corresponding microstructure evolution was studied employing transmission electron microscopy. The results show that domain boundaries are induced under repeated electric field application, and the microstructures become more complicated due to domain intersection. The mobility of domain boundaries degrades and the polarization of the material decreases because the intersection of domain boundaries introduces enormous strain fields and defects in the materials. A large number of dislocations and microcracks were observed in some regions when the specimens were repeatedly loaded for 106 cycles. In contrast, the remanent polarization of the ferroelectric PNZST degraded to 83% of its initial value and only half of the degraded polarization was recoverable after a refresh treatment, indicating that defects in grains play important roles in fatigue properties.