Dielectric Relaxation and Charged Domain Walls in (K,Na)NbO3-Based Ferroelectric Ceramics

The influence of domain walls on the macroscopic properties of ferroelectric materials is a well known phenomenon. Commonly, such “extrinsic” contributions to dielectric permittivity are discussed in terms of domain wall displacements under external electric field. In this work, we report on a possible contribution of charged domain walls to low frequency (10-106 Hz) dielectric permittivity in K1-xNaxNbO3 ferroelectric ceramics. It is shown that the effective dielectric response increases with increasing domain wall density. The effect has been attributed to the Maxwell-Wagner-Sillars relaxation. The obtained results may open up possibilities for domain wall engineering in various ferroelectric materials. © 2017 Author(s).The equipment of the Ural Center for Shared Use "Modern Nanotechnology" UrFU has been used. The research was made possible by the Ministry of Education and Science of Russian Federation (UID RFMEFI58715X0022). The authors acknowledge E. L. Rumyantsev and M. Morozov for useful discussion