Effect of polarization fatigue on the Rayleigh coefficients of   ferroelectric lead zirconate titanate thin films: experimental evidence and   implications
  The effect of polarization fatigue on the Rayleigh coefficients of ferroelectric lead zirconate titanate (PZT) thin film was systematically investigated. It was found that electrical fatigue strongly affects the Rayleigh behaviour of the PZT film. Both the reversible and irreversible Rayleigh coefficients decrease with increasing the number of switching cycles. This phenomenon is attributed to the growth of an interfacial degraded layer between the electrode and the film during electrical cycling. The methodology used in this work could serve as an alternative non-destructive way for evaluating the fatigue endurance and degradation in dielectric properties of ferroelectric thin-film devices during applications. 
X.J. Lou, H.J. Zhang, Z.D. Luo, F.P. Zhang, Y. Liu, Q.D. Liu, A.P.   Fang, B. Dkhil, M. Zhang, X.B. Ren, H.L. He
cond-mat.mtrl-sci