With a strong chemical sensitivity, high-resolution high angle annular dark field (HADDF)-scanning transmission electron microscopy (STEM) is widely used for acquiring detailed structural information in materials. The precise displacement of B-site ions with respect to the center of A-site ions in perovskites can be further mapped which is direct evidence for topological structures. As the topological entities have great potential in applications for future nanoelectronics such as memories, the results provide critical insights into understanding their fundamental properties. Examples of flux-closure vortexlike domain structures in bismuth ferrite (BiFeO3) and interaction between monolayer molybdenum disulfide (MoS2) and lead zirconate titanate (PbZr1-xTixO3) will be shown.
About the presenter
Yangyang Zhang is a PhD student working with CI Nagy Valanoor at UNSW.