Constitutive relation of electric fatigue on the ferroelectric ceramics
Domain switching under an electric filed has been recognized as a fundamental origin causing deterioration and failure of the properties for ferroelectric ceramics. Based on the variations of the in-situ XRD and the macroscopic phenomenological constitutive formulation for PLZT, the present paper formulates the hysteresis loops and the strain loops of ferroelectric ceramics induced by electric fatigue. Considering the domain-wall pinning and depinning coexist during electric fatigue cycling, we simulate the remanent polarization, the ration of different domains and ration of switching domains. Furthermore we present numerically the hysteresis loops and the strain loops of poled and unpoled ferroelectric ceramics induced by electric fatigue. It is found the present results have the good quantitative agreement with experimental data of PLZT. The present model is applicable to describe electric fatigue of the ferroelectric thin film.