Probing Nanoscale Ferroelectric Domain Switching Mechanisms with Scanning Probe Microscopy

Ferroelectric domains and domain walls have been a focus topic for research, owing to their applications in memory devices, ultrasonic imaging devices, etc. Recently, ferroelectric domain walls have been demonstrated to exhibit a rich panoply of nanoscale switching behaviors (V. R. Aravind \textit{et al,} Physical Review B \textbf{82}, 024111 (2010)). In this presentation, we report our study of domain reversal and polarization relaxation behavior of ferroelectric domain walls under localized electric field provided by a scanning probe microscope tip. Our studies show the relaxation behaviors differs at different distances from a 180 degree domain wall, throwing light on the microscopic mechanisms of polarization reversal.