Phase transitions in ferroelectric-paraelectric superlattices: Stability of single domain state

Abstract

We studied stability of the single-domain state with respect to domain formation within Landau-Ginzburg-Devonshire theory for ferroelectric-paraelectric superlattices having equal layer thickness. Single-domain state is possible if dielectric constant of the paraelectric is larger than that of the ferroelectric for non-polar directions as in the BaTiO3/SrTiO3 system, which was taken as an example. Stability limit of the single-domain state is found as a function of temperature and layer thickness where we show a strong dependence of this limit on character of near-electrode regions, a point often overlooked. We also show that transition between single- and multi-domain states is discontinuous.