Abstract
TEM studies on domain structure in PbTiO3 thin film show that the domain density depends on the grain size and indirectly on the film thickness. The mobility of domain walls (DWs) has been investigated by in situ TEM and mechanical dissipation techniques, and its contribution to the permittivity (ϵ) and coercive field (Ec) was analyzed. The weak pinning of DWs in SrBi2Ta2O9 (SBT) was further confirmed by experimental results of the voltage and frequency dependence of the fatigue as well as retention.