ELECTRIC FATIGUE IN LEAD-ZIRCONATE-TITANATE CERAMICS

Electric fatigue is a major obstacle for some potential applications of ferroelectric materials based on reversals of spontaneous polarization, such as memory devices and high strain actuators. Our studies of fine-grained hot-pressed lead zirconate titanate with lanthanum dopant (PLZT 7/68/32) show that fast fatigue is actually caused by contaminated surfaces instead of intrinsic structure deterioration or the change of domain states. All of the specimens with conventionally cleaned surfaces showed significant fatigue after 10(5) switching cycles, but specimens cleaned with a new cleaning procedure did not fatigue even after more than 10(8) switching cycles. This type of fatigue is found to be due to generated microcracking at the ceramic-electrode interface.