Fatigue resistance in lead zirconate titanate thin ferroelectric films: Effect of cerium doping and frequency dependence

We demonstrate improvement in fatigue resistance and other ferroelectric properties through cerium doping in sol-gel derived lead zirconate titanate thin films. We have studied frequency dependence of fatigue behavior and show that the loss of polarization due to fatigue follows a universal scaling behavior with N/f(2), where N is the number of switching cycles and f the frequency. The origin of the scaling is attributed to the drift of oxygen vacancies, which is the rate limiting process in the growth of the interface layer responsible for fatigue. Empirical fits for both undoped and cerium-doped samples show that switchable polarization follows stretched exponential decay with time or N/f. Cerium doping is shown to improve fatigue resistance by impeding the motion of oxygen vacancies. (C) 1996 American Institute of Physics.