A surface-layer model of ferroelectric nanowire

In this paper, a surface-layer model is established to study the axial polarization distributions and critical diameters of nanowires with different surface compositions. Analytical solutions are obtained based on this model, which are validated by the ab initio results for small-size nanowires and can also predict the behaviors of large-size specimen. Compared to the traditional Landau-Ginzburg-Devonshire theory using an extrapolation length, the present model describes more microstructure information of the surface-layer, and is thus capable of characterizing the influences of different surface compositions. Furthermore, this model may shed insight into the mechanisms of the size effect and polarization distribution patterns in nanoscale ferroelectrics.