ELECTRIC FATIGUE IN LEAD-ZIRCONATE-TITANATE CERAMICS

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