Landau-ginzburg theory of phase transition of ferroelectric superlattices

A Landau-Ginzburg theory of the phase transition of a one-dimensional ferroelectric superlattice is presented, where the superlattice is composed of a ferroelectrics of thickness L I and a paraclectrics of thickness L-2, which couple each other through the polarization at the interface. The expression for determining the transition point from the paraelectric state to the ferroelectric state is obtained in terms of the model parameters.