Formation and manipulation of domain walls with 2 nm domain periodicity in BaTiO₃ without contact electrodes

Abstract

In situ contactless formation and switching of two nanometre periodic ferroelectric domains in BaTiO3.

Engineering Individual Oxygen Vacancies: Domain-Wall Conductivity and Controllable Topological Solitons

“…To show controllability of the vacancies, first, the atomic structure of an unperturbed crystal was mapped ( Figure 1 C). Figure 1 D shows the same area after successful intentional in situ formation of an oxygen vacancy within a domain wall (details about the domain-wall formation procedure are provided in ref ( 54 )).…”

“…Single-crystal BaTiO 3 50 nm crystallites were used, providing strain-free bulk-like behavior, while yet allowing sufficient electron transparency to aid the TEM analyses. Recently, it has been shown that ferroic domain walls can be formed, moved, and switched contactless in such materials in situ during atomic-scale TEM imaging. , Here, we used this method to form the domain-wall structure, which served as a template for the oxygen vacancies. The guiding hypothesis was that oxygen vacancies are formed at a window dosage above the value that forms the domain walls and before the material is damaged.…”

“…The oxygen-vacancy manipulation presented in this work was obtained with the electron beam at a certain dosage window. Previous works showed that for dosage values less than 4 × 10 –4 nA/nm 2 , the dominant interaction of the sample and the electron beam is electromagnetic, rather than, say, local heating, resulting in domain-wall formation and switching. , Moreover, it has been shown that for dosage values greater than or equal to 270 nA/nm 2 , the electron beam interacts locally with the sample, giving rise to cation escape and even to atomic-scale etching of the material . In the current work, it was shown that individual oxygen-vacancy engineering is possible at the dosage window between these two values.…”

“…Commercially available single-crystal BaTiO 3 nanoparticles of 50 nm size 54 , 59 , 76 were purchased from US Research Nanomaterials, Inc. (99.9% pure). To evenly spread the particles on the TEM grid, the particles were suspended in ethanol and sprayed on the amorphous carbon-coated holey Cu grid using nitrogen gas.…”

Dynamic response and roughening of ferroelectric domain walls driven at planar electrode edges

“…Our observations of progressively increasing roughness as initially flat domain walls move through the disorder landscape are particularly pertinent for potential ferroelectricbased racetrack memory applications [25][26][27][28], where the resulting broadening of the information-carrying region could prove a significant limiting factor. A possible solution would be to focus on ferroelastic ferroelectric domain walls [57][58][59], where additional strain terms could help maintain straighter walls.…”