Domain Wall Conduction in Ferroelectrics

In the review we demonstrate correlation of the polarization vector structure with domain walls conductivity in ferroelectrics, multiferroics, ferroelastics, and related materials. In particular, free carriers type and accumulation degree strongly depend on the wall incline and rotation angles with respect to the spontaneous polarization, crystallographic axes, and temperature. The wall polar structure is determined by the interplay between Ising, Bloch, and Neel components, at that the flexoelectric coupling can induce or/and strongly depend on the Neel component of polarization across the nominally uncharged walls. Ultra-strong carrier accumulation is predicted for the walls with maximal incline angle.