Screening and size effects on the nanodomain tailoring in ferroelectrics semiconductors

The study of ferroelectric nanodomain tailoring attracts a growing interest not only owing to its possible applications in many fields of nanotechnology, such as various nanostructures engineering and high-density memories, but also it can clarify the physical nature of size, surface and interface effects appearing under the nanoscale polarization reversal in ferroelectric media. In this paper we evolved the thermodynamic theory of nanodomain tailoring in ferroelectric semiconductors allowing for semiconducting properties, screening, and size effects. Our analytical results prove that domain nucleation is similar to the first order phase transition. This conclusion completely agrees with recent theoretical predictions and voltage thresholds observed in Pb(Zr,Ti)O₃ and LiTaO₃ thin films. We obtained the theoretical dependence of an equilibrium nanodomain radius on the applied voltage in BaTiO₃, LiNbO₃ bulk ferroelectric semiconductors, LiTaO₃, Pb(Zr,Ti)O₃ thin ferroelectric films and demonstrated good agreement with the experimental data. Our results will help researchers not only to achieve reliable understanding of the physical process that takes place during the nanoscale polarization reversal in ferroelectric semiconducting media, but also to determine the necessary experimental conditions in order to obtain stable nanodomains with minimum lateral sizes and thus to increase an information density up to 90--3000.3em0exGbit∕cm².