Polarisation kinetics of electrically connected electroconductive ferroelectric multilayer structures

In this article, the polarisation kinetics of an electrically connected ferroelectric bimorph structure is described with an electric model by means of equivalent circuit analysis. This model results in a system of ordinary differential equations (ODEs) that can be solved numerically. A bimorph model structure consisting of wire-connected layers of barium–titanate–stannate ceramics was poled. The conductivities of the layers can be estimated by comparing of the measured electric field in the layers and the results of the poling model. In order to consider hysteretic effects, the Preisach model of hysteresis is included into the poling model. Within the ODEs, the slope of the hysteresis loop is needed. An algorithm for estimating it via the Preisach model was developed. This approach is based upon linear interpolation between adjacent grid points of the discretised electric field within the Preisach model. An example shows the capabilities of this method for considering poling, switching effects and depolarisation.