Creation of the Cogged Charged Domain Wall by Local Switching in Lithium Niobate

We have studied experimentally the shape evolution of the interacting initial head-to-head (h2h) and tail-to-tail (t2t) charged domain walls (CDW) and growing isolated domain in the Y-cut LiNbO3 plates. The wedge-like domains were created and grew by electric field application using biased tip of scanning probe microscope. Two h2h and one t2t initial CDWs have been produced during phase transition in the crystal with composition gradients created by in-diffusion and out-diffusion of Li. The formation and growth of cogged CDW has been revealed for domain interaction with t2t CDW in contrast to h2h CDW. Near the t2t CDW domain elongation is slowed down, while the widening of the domain part with neutral walls continues. The growth anisotropy leads to formation of the region with increased local tilt and formation of cogged CDW by generation of additional spikes. The obtained effects were considered in terms of kinetic approach to domain wall motion considering abnormal local field distribution in the vicinity of initial CDW with effectively screened depolarization field. The discovered effect can be considered for domain wall engineering thus paving the way for manufacturing of the nanoelectronics devices based on the CDWs.