Polarization and Dielectric Behaviors of Antiferroelectric-Ferroelectric Superlattices

Abstract

We propose a thermodynamic model to investigate the polarization and dielectric behaviors of antiferroelectric–ferroelectric (AFE–FE) superlattices by taking into account the electrostatic coupling effect. Coupling at the interface between the AFE and FE layers is mediated by local polarizations, which favors an FE ordering. The Kittel’s model of antiferroelectricity is employed to describe the free energy of AFE layer, whereas the free energy of the FE layer is described by the Landau-Ginzburg theory. Polarization and dielectric susceptibility are calculated as a function of temperature. Our results show that when interface coupling is increased, AFE ordering is enhanced in the FE layer while FE ordering is favored in the AFE layer and superlattice. Also, abrupt changes of dielectric susceptibilities are observed during FE-FI phase transition.

KEYWORDS:

• Ferroelectrics
• antiferroelectrics
• polarization
• dielectric
• superlattices

Additional information

Funding

K.-G. Lim acknowledges the support from Fundamental Research Grant Scheme, Ministry of Higher Education Malaysia (FRGS/1/2018/STG02/USMC/03/1). C.Y. Lum acknowledges the support of MyBrain15 under Ministry of Higher Education Malaysia.