Dresden 2020 – scientific programme
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KFM: Fachverband Kristalline Festkörper und deren Mikrostruktur
KFM 15: Postersession KFM
KFM 15.17: Poster
Thursday, March 19, 2020, 16:00–18:30, P2/1OG
3D Chemical Mapping of Nanostructural Features in Ferroelectrics by Atom Probe Tomography — •Kasper A. Hunnestad, Jan Schultheiß, Theodor S. Holstad, Antonius T. J. van Helvoort, and Dennis Meier — Norwegian University of Science and Technology, Trondheim, Norway
The functional properties of materials are intimately related to the atomic-scale structure and chemistry in all three dimensions. While conventional high-resolution electron microscopy (HREM) techniques enable visualization of the atomic structure, they lack depth resolution of the chemical composition. Atom Probe Tomography (APT) is an advanced analytical method that allows 3D quantitative mapping of the chemical composition with better than 100 ppm sensitivity and sub-nanometer spatial resolution. Combining the two techniques, both atomic structure and chemical composition of nanoscale features become accessible.
Here, we apply correlated HREM and APT measurements to ferroelectric domain walls (DWs) to understand the origin of their complex nanoscale properties. Using a Focused Ion Beam DWs are extracted into APT specimens from a model ferroelectric single crystalline system (hexagonal manganite, ErMnO3). Subsequently, HREM is used to locally identify and characterize the DWs in the specimens and provide information about the exact DW geometry and atomic structure. Based on first APT test measurement 3D chemical maps of up to 100x100x550 nm3 are gained, providing insight into the local chemistry at ferroelectric DWs with unprecedented precision.