Regensburg 2022 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 18: Poster Session 2
MM 18.29: Poster
Dienstag, 6. September 2022, 17:30–20:00, P2
Fractal abnormal grain growth in nanocrystalline Pd-Au at the atomistic level — •Johannes Wild1, Torben Boll1, Jules Dake2, Dorothée Vinga Szabó1, Stefan Wagner1, Carl E. Krill2, and Astrid Pundt1 — 1Karlsruhe Institute of Technology (KIT), Institute for Applied Materials - Materials Science and Engineering (IAM-WK), Karlsruhe, Germany — 2University of Ulm, Institute of Functional Nanosystems, Ulm, Germany
Nanocrystalline (NC) Pd-10 at.% Au (PdAu) prepared by inert gas condensation (IGC) shows an unconventional manifestation of abnormal grain growth upon heat treatment. This unusual growth mode leads to complex and highly convoluted boundaries resembling those of fractal shapes. Furthermore, the microstructure shows a bimodal grain size distribution with regions of NC grains bordering grains in the micron range. This phenomenon is unique to this NC PdAu as conventionally prepared samples showed normal grain growth for the same heat treatment. In this study, we investigate the abnormal grain boundaries of heat-treated IGC PdAu using atom probe tomography (APT) and field ion microscopy (FIM). The position-specific APT samples are produced by targeted sample preparation with focused ion beam lift-out methods at chosen regions of interest that are identified beforehand by high-resolution electron backscatter diffraction imaging. We also use FIM, which has a higher lateral resolution than APT. This research is financially supported by the Deutsche Forschungsgemeinschaft (DFG) via project number 461632490, DFG PU131/18-1, DFG KR1658/10-1 and Karlsruhe Nano Micro Facility (KNMFi).