Local phase decomposition as a cause of polarization fatigue in ferroelectric thin films

We show that lead zirconate titanate thin films undergo local phase decomposition during fatigue. The original remanent polarization of the fatigued film is completely restored after furnace annealing in an O-2 atmosphere, following a significant regrowth of a perovskite phase from the pyrochlorelike structure. By comparing our data with other researchers' work on annealing of fatigued ferroelectric samples, we conclude that local phase separation is the generic reason for electrical fatigue in ferroelectrics. A fatigue model is proposed in order to interpret our experimental data.