Imaging and structure analysis of ferroelectric domains, domain walls, and vortices by scanning electron diffraction

Direct electron detectors in scanning transmission electron microscopy offer unprecedented nanoscale structure analysis capabilities. This study uses scanning electron diffraction (SED) to investigate local polar distortions in the uniaxial ferroelectric Er(Mn,Ti)O₃. A custom convolutional autoencoder with bespoke regularization disentangles subtle scattering variations of ferroelectric domains, domain walls, and vortex textures, separating them from extrinsic factors. This method enables quantitative measurement of symmetry-breaking distortions across large areas, mapping structural changes at interfaces and topological structures with nanoscale resolution.

Ursula Ludacka, Jiali He, Shuyu Qin, Manuel Zahn, Emil Frang Christiansen, Kasper A. Hunnestad, Xinqiao Zhang, Zewu Yan, Edith Bourret, István Kézsmárki, Antonius T. J. van Helvoort, Joshua Agar, Dennis Meier