Persistence of Acentricity in Doped Ferroelectrics through Changes in Chemical Bonding*

Although broken inversion symmetry is traditionally thought to be stabilized primarily by long-range interactions, numerous noncentrosymmetric semiconductors (NCSs) have been shown to retain their broken inversion symmetry at dopant concentrations more than sufficient to screen long-range interactions [1]. Despite the identification of short-range interactions as a key component in stabilizing acentricity, the precise mechanism behind this phenomenon remains unclear. We use density functional theory to investigate the effect of doping on the prototypical ferroelectric BaTiO₃, focusing on changes in local chemical bonding as a potential explanation for the short-range interactions stabilizing the distortion.
[1] Zhao et al., Phys. Rev. B, 97(5), 054107 (2018)