A model for the double loop of ferroelectric polarization close to TC

Abstract

For ferroelectrics with a phase transition of the first order a double hysteresis loop of the polarization can be found close to TC. This behavior is explained using the Weiss field model taking into account that strain in the ferroelectric is induced by the polarization via the piezoeffect. The Weiss field model is looked at as a feedback loop where the polarization influences itself by the electrostatic interaction between the constituent dipoles.