Dresden 2026 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 30: Interface Controlled Properties, Nanomaterials, and Microstructure Design II
MM 30.2: Talk
Thursday, March 12, 2026, 10:30–10:45, SCH/A215
Revealing nanovoids in growth-resistant regions of nanocrystalline Pd–Au using atom probe tomography — •Johannes Wild1, Fabian Andorfer4, Svetlana Korneychuk2,3, Jules M. Dake4, Dorothée Vinga Szabó1,2,3, Stefan Wagner1, Carl E. Krill III4, and Astrid Pundt1,2 — 1Institute for Applied Materials, Karlsruhe Institute of Technology — 2Institute of Nanotechnology, Karlsruhe Institute of Technology — 3Karlsruhe Nano Micro Facility (KNMFi), Karlsruhe Institute of Technology — 4Institute of Functional Nanosystems, University of Ulm
Nanocrystalline Pd–Au produced by inert gas condensation (IGC) shows extreme abnormal grain growth (AGG) upon heat treatment. In some cases, narrow regions of residual nanocrystalline material resist coarsening entirely, persisting between abnormally grown grains exceeding 100 µm. We investigate these growth-stagnant regions using site-specific SEM/FIB lift-outs, atom probe tomography (APT) and TEM. FIB cross-sections reveal that these nanocrystalline regions are significantly more porous than the surrounding matrix, and APT reconstructions from them exhibit a strongly elevated density of OH-containing clusters, which are largely absent elsewhere. By analysing local ion-density variations during field evaporation into voids, we show that these OH clusters correspond to nanovoids in the material. Correlating porosity with grain morphology, we find that the most porous regions exhibit the strongest resistance to grain growth, indicating that nanoscale porosity is a key factor in stabilizing the nanocrystalline grain structure in IGC Pd–Au (manuscript submitted).
Keywords: abnormal grain growth (AGG); palladium; gold; atom probe tomography (APT); nanoscale porosity