Modelling of Domain Wall Motion, Nonlinear Dielectric Response and Defect Effects

Abstract

Ferroelectrics are perspective materials for information technology and data storage. The extremely narrow domain wall width and the capability to manipulate polarization by electric field opens the pathways toward ultrahigh storage densities. These materials have important applications in modern telecommunications and power electronic due to their tunable properties. Ferroelectric nonlinear dielectric properties are strongly determined by domain wall motion. To enhance the performance of existing ferroelectric devices and to develop new technical applications it is necessary to deeper understand the physics of domain walls as well as the role of microstructural factors and externals fields in the response of these materials. With this project, we intend to study how different kind of defects (acceptor, donor and charged walls) affect domain wall motion and dielectric response. As theoretical framework, we propose to use the model of effective potential which provides a simplified description of domain wall motion, and which is suitable to introduce defects as perturbation. In a first stage, different kinds of defects will be modeled. Latter, in a second stage, it will be studied the effect of the concentration of these defects on domain wall dynamic and nonlinear response. We expect to contribute to the advances of technical application of these materials and the domain walls engineering.