Electric field control of piezoelectricity in textured PMN-PZT ceramics

Ferroelectric ceramics generally develop macroscopic piezoelectric effects only after undergoing suitable electric field treatment, referred to as poling. In this study, we examine the influence of various poling conditions, including both direct current (DC) and alternative current (AC) electric fields, as well as temperature, on the piezoelectric properties of [001]-textured PMN-PZT ceramics. The results show that the piezoelectric properties under alternative current poling (ACP) condition include d₃₃ = 1330 pC/N, ɛ_r = 3280, and k₃₁ = 0.646. ACP shows a 9 % increase in d₃₃ compared to direct current poling (DCP). Increasing the temperature during DCP can raise d₃₃ to 1350 pC/N and k₃₁ to 0.66, with a high T_R−T of 121 °C. Due to the influence of grain boundaries, there is a significant difference between [001] textured ceramics and single crystals, as the domain structure switching and growth are constrained by orientation differences between grains. Phase-field simulations further reveal that the growth of domains is impeded by grain boundaries in polycrystals, which hinders the formation of larger-size domains. The results suggest that ACP may be more effective in larger grains in textured ceramics.