Impact of Domain Wall Conduction on Ferroelectric Domain Reversal Kinetics

Recent discovery and exploration of domain wall conduction in ferroelectrics promises to substantially modify the concept of the polarization reversal. We show by example of lithium niobate that the presence of domain wall conduction not only resolves the long standing problem of non-realistically high domain formation energy, but also leads to the exponential electric field dependences exp(–E_n/E) and exp(–E_l/E) for the rates of nucleation (n) and lateral (l) growth with characteristic fields E_n ≈ 75 and E_l ≈ 15 kV/mm. The kinetics of the polarization reversal shows distinct stages of nucleation, lateral growth, and coalescence of separate domains. It corresponds, in agreement with experiment, to the common exponential law exp(\({{E}_{*}}\)/E) for the reversal time with E_l < \({{E}_{*}}\) < E_n. To the best of our knowledge, this study is the first one explaining theoretically this law.