Atomic-scale mapping of dipole frustration at 90° charged domain walls in ferroelectric PbTiO3 films

Abstract

The atomic-scale structural and electric parameters of the 90° domain-walls in tetragonal ferroelectrics are of technological importance for exploring the ferroelectric switching behaviors and various domain-wall-related novel functions. We have grown epitaxial PbTiO3/SrTiO3 multilayer films in which the electric dipoles at 90° domain-walls of ferroelectric PbTiO3 are characterized by means of aberration-corrected scanning transmission electron microscopy. Besides the well-accepted head-to-tail 90° uncharged domain-walls, we have identified not only head-to-head positively charged but also tail-to-tail negatively charged domain-walls. The widths, polarization distributions, and strains across these charged domain-walls are mapped quantitatively at atomic scale, where remarkable difference between these domain-walls is presented. This study is expected to provide fundamental information for understanding numerous novel domain-wall phenomena in ferroelectrics.

On the benefit of aberration-corrected HAADF-STEM for strain determination and its application to tailoring ferroelectric domain patterns

“…The background pressure was 10 À 5 Pa and the substrate temperature was kept at 650°C. During the growth of the PbTiO 3 layers, an oxygen pressure of 20 Pa, a laser repetition rate of 5 Hz and a laser energy density of 2 J cm À 2 were used [37]. Cross-sectional samples for the STEM experiments were prepared by slicing, gluing, grinding, dimpling, and finally ion milling.…”

Atomic-Environment-Dependent Thickness of Ferroelastic Domain Walls

“…[1,19,22,24,40] Further, we also find asymmetric thickness of ferroelastic domain walls in the same domain due to the strain effect form the misfit dislocation. Although anomalously thick domain walls have also been reported for charged 90° domain walls, [17,41] the head-to-tail configuration in this case can exclude the significant charge effect. The coexistence of varied width of domain wall in ferroelectrc thin films implies us that the atomic structure of domain wall is highly depends on the atomic environments due to their complicate coupling with interfaces, dislocations and other domain walls.…”

General nature of the step-induced frustration at ferromagnetic/antiferromagnetic interfaces: topological origin and quantitative understanding

“…An exciting path for the implementation of our analysis lies in its applicability to ferroelectric systems where frustration induced domain walls have also been observed and where the domain wall width has been found to increase with thickness at ultrathin region [51]. In both the ferromagnetic and the ferroelectric applications, one can proceed to consider the effect of overlapping domain walls when the step edge defects may interfere.…”