Giant domain wall contribution to the dielectric susceptibility in BaTiO3 single crystals

Abstract

Giant domain wall contribution to the dielectric susceptibility was observed in the rhombohedral phase of BaTiO3 single crystals. The unusual contribution can be two orders of magnitude larger than the thermodynamically estimated lattice susceptibility, even at driving fields that are much smaller than the coercive field. Nonlinearity measurements suggest a local sliding motion of depinned domain walls being responsible for the ultrahigh susceptibility. Pretreatments, particularly those performed in high temperature ferroelectric phases, can strongly affect the contribution of this local sliding mechanism.