Electrostatic Model for the Dielectric Permittivity of Ferroelectric Films with 90° Domain Structures

We propose a simple electrostatic model for ferroelectric films with an a -domain variant embedded up to a given fraction in a c -domain, based on the electrostatics of inhomogeneous ferroelectric systems with anisotropic properties. The practical aim of this study is to establish the dielectric permittivity dependence on a - or c -domain fraction and compare it with experimental results. The dielectric permittivity is calculated intrinsically by averaging the electrostatic contributions from a - and c -domain variants. Subsequently, analytical approximations for the electric potential and dielectric permittivity are obtained from an equivalent circuit analysis and conclusions are drawn with respect to fitting of real data with simple model relationships.