Origins of domain wall pinning in ferroelectric nanocapacitors

We have investigated domain wall pinning and its origins in ferroelectric nanocapacitors using piezoresponse force microscopy. Domain wall pinning of two different types was observed in the nanocapacitors. The first type of pinning originates from local point defects similar to previous reports. The second one originates from immobile local defects in the place of pristine domains. In both cases, pinning and de-pinning processes were observed without significant domain wall bowing. The results can be helpful to understand domain wall motion and improve the reliability of nanoscale ferroelectric memory devices.