B03 – Local chemical composition of defects

PI: Marcus Hans (Chair of Materials Chemistry, RWTH Aachen)

SFB researcher: Deborah Neuß (Chair of Materials Chemistry, RWTH Aachen)

The aim of this project is the contribution towards identifying defect phases based on changes in chemical composition, and thus chemical potential. Grain boundaries and precipitates of Ni-Cu-Nb solid solutions as well as intermetallic Nb7(Ni,Al)6 and Nb7(Ni,Cu)6 phases will be characterised spatially-resolved using atom probe tomography. The second aim of this project is the controlled synthesis of defect phases using a unique in vacuo experimental setup together with project B02. Samples and specimens of interest will be kept under vacuum throughout the entire processing to avoid influences from the ambient atmosphere and atom probe specimens will be prepared using reactive nitrogen and oxygen plasmas. Surface ion implantation as well as grain boundary decoration will be carried out with these nitrogen and oxygen probes. In addition, high-resolution TEM investigations will be done in collaboration on selected samples with projects A03, B01 and B06. Thereby, high resolution structural and chemical information of defects can be correlated.

Publications:

[1] D. Neuß, I.E. McCarroll, S. Zhang, E. Woods, W.J. Delis, L. Tanure, H. Springer, S. Sandlöbes, J. Yang, M. Todorova, D. Zander, C. Scheu, J.M. Schneider, M. Hans (2024) High-resolution chemical and structural characterization of the native oxide scale on a Mg-based alloy, Corrosion Science 227, pp. 111776 – https://doi.org/10.1016/j.corsci.2023.111776

[2] S. Zhang, Z. Xie, P. Keuter, S. Ahmad, L. Abdellaoui, X. Zhou, N. Cautaerts, B. Breitbach, S. Aliramaji, S. Korte-Kerzel, M. Hans, J.M. Schneider, C. Scheu (2022) Atomistic structures of <0001> tilt grain boundaries in a textured Mg thin film, Nanoscale 14, pp. 18192 – https://doi.org/10.1039/d2nr05505h

[3] S. Aliramaji, P. Keuter, D. Neuß, M. Hans, D. Primetzhofer, D. Depla, J.M. Schneider (2022) Effect of growth temperature and atmosphere exposure time on impurity incorporation in sputtered Mg, Al, and Ca thin films, Materials 16, pp. 414 – https://doi.org/10.3390/ma16010414

[4] M. Hans, P. Keuter, A. Saksena, J.A. Sälker, M. Momma, H. Springer, J. Nowak, D. Zander, D. Primetzhofer, J.M. Schneider (2021) Opportunities of combinatorial thin film materials design for the sustainable development of magnesium-based alloys, Scientific Reports 11, pp. 17454 – https://doi.org/10.1038/s41598-021-97036-6