The Weiss model and the Landau-Khalatnikov model for the switching of ferroelectrics

It is shown that the molecular field theory by P. Weiss formally leads to the switching kinetics of ferroelectrics, which is described by the well-known Landau-Khalatnikov equation. The switching has a critical character, taking place only at Ea>Ec (Ea: external field, Ec: coercive field). The results are checked by computer simulations.