Hysteresis Curve of X-Ray Diffraction Peak Intensity in Lead Zirconate Titanate Ceramics

A new system has been developed for the measurement of motion of ferroelectric domains under high electric field driving in ferroelectric materials. This system can simultaneously measure the hysteresis curves of (hkl) X-ray diffraction peak intensity (I(hkl)), field-induced polarization (D), and switching current (I current) as a function of electric field. In a poled tetragonal lead zirconate titanate ceramic, it was found that the peak of I current occurs before the abrupt change in X-ray diffraction intensity of I 002 (=I(002)/{I(002)+I(200)}) in the negative direction of the poling axis, whereas the peak of I current in the positive direction of the poling axis occurs at the same electric field as the abrupt change in the X-ray diffraction intensity of I 002 under ±2000 V/mm triangular-waveform high electric field at a frequency of 1 mHz. Domain motion is suggested as follows: 180 deg domain walls move before 90 deg domain walls in the negative direction of the poling axis, and 180 deg domain walls move together with 90 deg domain walls in the positive direction of the poling axis near coercive electric fields. This is probably due to the existence of asymmetry of internal bias electric/stress field. Several discussions are given on the relationships among the hysteresis curves of X-ray diffraction peak intensity, field-induced strain, dielectric coefficient, and piezoelectric d 33 coefficient in the tetragonal ceramics.