As well-known and well-used ferro- and piezoelectric materials, lead zirconate titanate (Pb (Zr,Ti) O3, PZT) ceramics have been of high interest for over 50 years. Researches on PZT have made great progress, whereas many basic issues remain insufficiently understood. For example, the progressive loss of switchable polarization due to electrical and mechanical cycling, i.e., polarization fatigue, is a serious problem in device application of PZT.

Studies on the heterogeneity during the fatigue process are truly important to explore the origin of fatigue. However, combination investigations on the details of heterogeneity and the switching mechanism in ferroelectric ceramics are scarce.

So LI Jiwei and Zhang Yong of State Key Laboratory of New Ceramics and Fine Processing, Institute of Nuclear and New Energy Technology, Tsinghua University and CAI Hairong and YI Xiaoxing of Institute of Acoustics, Chinese Academy of Sciences carried out a series of studies and use the quasi-static method to measure d33 values point by point to obtain information about the switching retardation and heterogeneity behavior due to fatigue in PZT ceramic samples.

In the research, the variation of d33 values was measured on the samples with different fatigue states and different reverse switching pulses. The results demonstrate that apparent fatigue heterogeneity exists down to the millimeter scale across disc shaped samples 20 mm in diameter. The d33 contour plots on sample surface point to a strongly heterogeneous behavior. The switching behavior as a function of fatigue cycles indicates that the switching retardation exists in the different fatigue stages and increases with increasing cycle number. The d33 measurements exhibit a strongly heterogeneous behavior of fatigue.The observed fatigue heterogeneity is alleviated after serious fatigue.

This research result was published on the recently issued journal of JOURNAL of ELECTROCERAMICS (Volume 25, 2010, 135-139).