Berlin 2012 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 31: Nanocharacterization

MM 31.1: Talk

Wednesday, March 28, 2012, 10:15–10:30, H 1029

HR(S)TEM and TAP analyses of embedded Pb nanoparticles — •Anna Moros, Harald Rösner, and Gerhard Wilde — Westfälische Wilhelms-Universität Münster, Institut für Materialphysik, Wilhelm-Klemm-Str. 10, 48149 Münster

In the present work nanoscaled Pb particles embedded in an Al(Ga) matrix with 3 at.% Ga were processed by melt spinning. Using the ChemiSTEM technology integrated into a FEI Tecnai Osiris 200 kV microscope, elemental mappings have been performed and revealed Ga segregation at grain boundaries. This is a well known process (grain boundary poisoning) leading to an intergranular embrittlement of the Al matrix. However, Ga segregation also occurred at the nanoscaled embedded Pb particles. In order to investigate the particle-matrix interface precisely, high resolution micrographs were taken at the JEOL JEM-ARM 200F. Geometric phase analysis has been used to evaluate the strain state of the heterogeneous particle-matrix interface. It is shown, that the lattice parameter mismatch between the Pb particle and the Al(Ga) matrix is reduced in comparison with the AlPb composite. In order to verify whether the Ga is alloying with Pb or not, Tomographic Atom Probe (TAP) was used. These experimental results are presented and critically discussed. Funding by DFG is gratefully acknowledged.