Domains, domain walls, domain engineering, polar regions

J. Hlinka
Institute of Physics of the Czech Academy of Sciences, Prague, Czech Republic 

Properties and applications of the materials with ferroelectric or other kind of domains and domain walls will definitely belong to the most discussed subjects of this F2Cπ2 2019 joint meeting of ISAF-ICE-EMF-IWPM-PFM conferences. Our desire to address these naturally occurring topological defects calls for consideration of various domain engineering strategies. We aim to present the most general experimental and theoretical concepts that can be useful in related materials science activities. 
Finally, it is important to address the applicability of the concepts developed for macroscopic domains when the material of interest contains nanoscale domains or nanoscale polar regions, encountered for example in very thin films or  in considerations about relaxors and piezoelectricity of perovskite relaxor ferroelectrics.

In this tutorial presentation, aimed to facilitate discussion of the most recent achievements, I intend to cover the following subjects: 

1.    Macroscopic twins, transformation induced orientational and translational domains.
2.    Macroscopic symmetry breaking species, spontaneous vectors, tensors, bidirectors.
3.    Electromechanical compatibility.
4.    Symmetry of domain walls and applications.
5.    Multiferroic aspects of domains and domain walls.
6.    Domain engineering and domain wall engineering, average properties.
7.    Local domain wall properties, dynamics, switching, domain wall as a device.
8.    Prediction of domain wall properties, Bloch walls, walls in walls, line skyrmions.
9.    Nanoscale domains, polar nanodomains, polar nanoregions, relaxor ferroelectrics.
10.    Perspectives and challenges for future studies.