With an incredibly diverse portfolio of applications, ferroelectric oxides are already among the most useful functional materials, and yet their technological potential is far from being exhausted as their properties change dramatically when their dimensions are reduced. At the nanoscale, the behaviour of epitaxial ferroelectric heterostructures is governed by the electrical and mechanical boundary conditions at various interfaces, opening new opportunities for manipulating ferroelectricity and engineering new functionalities. In addition to the interfaces between chemically distinct components, domain boundaries, which separate regions with different orientations of the polarisation, play a key role in determining the macroscopic functional properties.

In this seminar we will explore how epitaxial strain and electrostatic boundary conditions can be used to engineer different types of ordered ferroelectric nanodomain structures, discuss methods for characterizing them using a combination of macroscopic electrical measurements, scanning probe microscopy and synchrotron X-ray nanodiffraction, and highlight some of the intriguing new phenomena such as negative capacitance that arise from the nanoscale motion of ferroelectric domain walls [1-3].

 [1]  P. Zubko et al. Phys. Rev. Lett. 104, 187601 (2010)

[2]  P. Zubko et al. Nano Lett. 12, 2846 (2012)

[3]  P. Zubko et al. Nature 534, 524 (2016)