Abstract
We studied theoretically the pinning-depinning transition of the domain wall on the surface of near-stoichiometric lithium niobate (NSLN) crystals. Based on the analysis of electrostatic interaction between the electrode and the sample surface, the detailed depinning mechanism of the domain wall at the pinning defect Nb-Li(4+) was shown. Using the classical shell-model, the critical parameter theta(c) for the domain wall at the reversal of Nb-Li(4+) was estimated to be 11 degrees and the domain wall energy per unit area for NSLN crystals was also calculated roughly as 1.3 J m(-2).