IN SITU XRD INVESTIGATION OF DOMAIN SWITCHING IN FERROELECTRIC CERAMICS PLZT DURING AN ELECTRIC FATIGUE PROCESS
原位XRD法研究电疲劳过程中铁电陶瓷PLZT的畴变

An in situ XRD method was employed to identify variations of electric domains on the surfaces of poled PLZT samples during an electric fatigue process, and simultaneously, the related remnant polarization was measured. The SEM observation revealed that the major fracture mode for fatigued samples is intergranular. The diffraction intensities, I(002) and I(200), after each cycle decreased and increased, respectively, and their magnitudes of the increment and decrement lowered as the number of cycles increased. It is suggested that the reduction in magnitude of remnant polarization is caused by the reduction in numbers of switch-able domains during a fatigue process. In addition, the incompatible high strain induced the intergranular micro-cracks in the material, which leads the major fracture mode for the fatigued sample to be intergranular. The formation and the elongation of micro-cracks in samples mainly occurred at earlier stage of electric fatigue.