The relationship between the switching field and the intrinsic defects in near-stoichiometric lithium niobate crystals

摘要

Several near-stoichiometric lithium niobate (LiNbO3) plates were prepared by the vapour transport equilibrium technique. Domain reversal was carried out on these samples by electric field poling. A nonlinear dependence of switching field on the concentration of anti-site niobium (Nb-Li(4+)) ions was observed. This nonlinear relationship was explained by a two-dimensional model based on the dynamics of the domain wall. A parameter of theta(c), denoting the critical position of the domain wall round Nb-Li(4+) ions, was introduced to describe domain reversal. The domain wall energy per unit area for near-stoichiometric lithium niobate was also roughly calculated to be larger than 0.27 J m(-2).