Dynamics of ferroelectric domain walls

Dielectric data obtained in the ferroelectric phase of KH2PO4 and Rb2ZnCl4 single crystals as well as in PZT-ceramics are provided demonstrating qualitatively similar behavior in quite different ferroelectric systems. The peculiar low frequency dispersion, nonlinearity, dielectric loss and ageing phenomena, respectively, reflect the creep-like dynamics of highly susceptible domain walls. The significance of the domain wall-defect interaction becomes evident from the crucial influence of impurity type and concentration, respectively. The experimental results are discussed in terms of theoretical concepts developed for elastic interfaces in quenched disorder. The physical nature of the pinned elastic domain walls requires new approaches to characterize the properties of ferroelectric materials.