Domain wall state diagram for SrTiO₃/BaTiO₃ superlattice structures

Abstract

The domain wall structure of ferroelectric/ paraelectric superlattices can be much more complex due to the influence of the superlattice stacking structure, the in-plane strain induced by the substrate and environmental temperature. In this study, we employed a phase field model to investigate the domain wall state of the SrTi[Formula: see text]/BaTi[Formula: see text] superlattice structure. The domain wall thickness for the SrTi[Formula: see text]/BaTi[Formula: see text] layer was measured using a hyperbolic function. Based on the simulation results, here, we show a domain wall state diagram to distinguish the hard and soft domain states. The polarization profiles across hard/ soft domain walls were illustrated and analyzed. Our simulation results offer a useful concept for the control of the domain wall state in the ferroelectric superlattice.