Surface potential at a ferroelectric grain due to asymmetric screening of depolarization fields

Abstract

Nonlinear screening of electric depolarization fields, generated by a stripe domain structure in a ferroelectric grain of a polycrystalline material, is studied within a semiconductor model of ferroelectrics. It is shown that the maximum strength of local depolarization fields is rather determined by the electronic band gap than by the spontaneous polarization magnitude. Furthermore, field screening due to electronic band bending and due to presence of intrinsic defects leads to asymmetric space charge regions near the grain boundary, which produce an effective dipole layer at the surface of the grain. This results in the formation of a potential difference between the grain surface and its interior of the order of 1 V, which can be of either sign depending on defect transition levels and concentrations. Exemplary acceptor doping of BaTiO3 is shown to allow tuning of the said surface potential in the region between 0.1 and 1.3 V.

14 pages, 11 figures, submitted to J. Appl. Phys

References in corpus (5)

• "Head-to-head" and "tail-to-tail" 180-degree domain walls in an isolated ferroelectric
• Modeling the electrical conductivity in BaTiO3 on the basis of first-principles calculations
• Drift of charged defects in local fields as aging mechanism in ferroelectrics
• Oxygen vacancy segregation and space-charge effects in grain boundaries of dry and hydrated BaZrO3
• Space-charge mechanism of aging in ferroelectrics: an exactly solvable two-dimensional model

Cited by in corpus (5)

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• Ferro-ionic States and Domains Morphology in Hf${}_x$Zr${}_{1-x}$O${}_2$ Nanoparticles
• Reentrant polar phase induced by the ferro-ionic coupling in Bi${}_{1-x}$Sm${}_x$FeO${}_3$ nanoparticles