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The domain switching dynamics was investigated in Nb-doped Pb(Zr 0.52 Ti 0.48 )O 3 bulk ceramics through observing systematically the evolution of the hysteresis loops at frequencies ranging from 0.01 to 100 Hz and in a field of 7.5–35 kV/cm. The experimental results indicate that the hysteresis loops are remarkably dependent on the fields and the frequencies. The data are analyzed by the Merz equation. The analysis results reveal that the requirement to satisfy the Merz equation is saturated loops. Based on these results, we divided the polarization switching process into three regions.

The scaling behaviors of the dynamic hysteresis in Zr-rich lead zirconate titanate bulk ceramics at various frequency ( f ) and field amplitude ( E 0 ) values, and in different ferroelectric phases, were investigated. The scaling laws of the hysteresis area 〈 A 〉 at fixed temperature take the forms 〈 A 〉 ∝ f 0.16 E 0 and 〈 A 〉 ∝ f 0.01 E 0 0.2 for low frequency and high frequency, respectively. The forms are different from those of the theoretical predictions and other experimental results but are the same for different ferroelectric phases, which implies that the compositions and crystal structures can influence the scaling laws while the different space groups in the rhombohedral phase can not.

The dependence of a switching current in lead zirconate titanate (PZT) ferroelectric ceramics on the temperature and an applied electrical field was investigated. It was found that temperature has a moderate contribution to the switching current values, but applied electric fields have significant effects on the values. Importantly, a relaxation of switching current on frequency was observed through this method. By a comparison investigation on PZT ceramics of different compositions non- 18 0 ∘ domain switching was found to be responsible for the relaxation. A function, the ‘active potential of domains’ was proposed to interpret the observed results from the viewpoint of energy. The results obtained provide a new understanding of domain process in ferroelectric ceramics that relaxation of domains is a collective motion of non- 18 0 ∘ domains.