Depolarizing field in temperature-graded ferroelectrics from an atomistic viewpoint

An atomistic approach for computing the depolarizing, or internal, electric field in materials with inhomogeneous polarization is developed. Application of the approach for studying the depolarizing fields in technologically important (Ba0.7Sr0.3)TiO3 ferroelectric alloy with temperature gradients has revealed the intrinsic features of these fields as well as their role in the establishment of polarization gradients. It is found that the depolarizing fields are inhomogeneous and can be tailored to yield both zero and non-vanishing potential drops. Such findings could pave the way to unusual thermoelectric materials, photovoltaics and locally conducting materials, all of which are at the frontier of current research. (paper)