Calculation of depolarizing fields in thin ferroelectric films with account of screening effects

We present a method for calculating depolarizing fields in thin ferroelectric films within the framework of a discrete model, taking into account effects of screening by free charges of the film material itself and the electrodes. The formulas for the energy of dipole-dipole interactions were obtained from the multipole expansion of the screened Coulomb potential. Calculations were performed using the periodic Green’s function method and the Ewald method. We found that the dependence of depolarizing field on the layer number in a monodomain film can be approximated by the sum of exponential functions. We also investigated the effect of screening parameters on the domain structure.