Identification of microscopic domain wall motion from temperature dependence of nonlinear dielectric response

摘要

It is known that the permittivity of ferroelectric polydomain films and single crystals in weak electric fields is strongly enhanced by the reversible movement of pinned domain walls. Two mechanisms of the movement exist: first, the bending of free segments of the domain wall and second the planar movement of the domain wall as a whole. In this work, we theoretically demonstrate that it is possible to determine the dominant mechanism of the reversible domain wall movement by means of a temperature measurement of a nonlinear macroscopic dielectric response. In addition, we demonstrate that using this approach, it is possible to obtain quantitative information on the microscopic distribution of the pinning centers. Thus, we suggest that this concept may serve as a simple and useful characterisation tool in the process of development of high-permittivity materials.