First-Principles Study of Polarization Behavior in BaTiO3/PbTiO3 Ferroelectric Superlattices

Abstract

We performed the first principle calculation to investigate the polarization behavior of BaTiO3(BTO)/PbTiO3(PTO) superlattices with a period-5 superlattice model. The results show that when BTO proportion increases, values of c/a increase and polarizations decrease. In BPT superlattices, polarization in each local layer keeps a constant value, indicating that short-period BPT superlattices can be approximately considered as a single ferroelectric material. Moreover, from analysis of the electrostatic model, we know the directions of internal electric fields in BTO and PTO layers are opposite. Internal electric field in PTO layer leads to polarization loss in this layer, but polarization in BTO layer is enhanced by internal electric field.