Dynamics of ferroelectric 180 degrees domain walls at engineered pinning centers

The interaction between domain walls and pinning centers in ferroelectrics is of great interest from both fundamental and practical points of view. In this work, we show that, counter to intuition, the apparent velocity of domain walls can increase as the defect density increases. However, when we closely investigate the propagating front of the domain wall, we find that it is not unified but can be rough, indicating the presence of multiple nucleated domains in advance of the primary wall. We therefore ascribe the increased apparent velocity with defect density to actually derive from nucleation-aided motion. To further investigate the effect of engineered pinning centers, we spatially confined the defect regions and then propagated domain walls in that direction. We found that, given a sufficiently high defect density, walls can be pinned indefinitely at sub-threshold voltages. Finally, we outline a method to create domain wall propagation channels in which the wall is confined to a low defect region bordered by high defect density regions. Published by AIP Publishing.