B01 – Atomic structure and composition of defect phases in Mg and Ni-based systems
PI: Christina Scheu (MPIE Düsseldorf)
SFB researchers: Siyuan Zhang (MPIE Düsseldorf)
In project B01, a combination of electron microscopy and spectroscopy techniques are applied to search for defect phases and determine their atomic structures. For example, we examined grain boundaries that are critical to transport properties of materials [1-4], and discovered new grain boundary phases [2]. We have developed correlative methods with atom probe tomography (project B03) to investigate the surface oxide phases on metals, which are fundamental to understand their corrosion properties [5, 6]. We also studied planar defects [7] and interfaces [8] in intermetallic systems, so that their relationship to the mechanical properties can be revealed (see the figure below). Algorithms were developed (Project A04) to extract atomic structures of bulk and defect phases from high resolution microscopy images [9], facilitating the comparison with atomistic simulations.
Publications:
[1] S. Zhang, Z. Xie, C. Scheu, et al. (2022) Atomistic structures of <0001> tilt grain boundaries in a textured Mg thin film, Nanoscale 14, 18192 – DOI: https://doi.org/10.1039/D2NR05505H
[2] R. Bueno Villoro, C. Scheu, S. Zhang, et al. (2023) Grain boundary phases in NbFeSb half-Heusler alloys: A new avenue to tune transport properties of thermoelectric materials, Advanced Energy Materials 13, 2204321 – DOI: https://doi.org/10.1002/aenm.202204321
[3] R. Bueno Villoro, C. Scheu, S. Zhang, et al. (2023) Fe segregation as a tool to enhance electrical conductivity of grain boundaries in Ti(Co, Fe)Sb half Heusler thermoelectrics, Acta Materialia 249, 118816 – DOI: https://doi.org/10.1016/j.actamat.2023.118816
[4] R. Bueno Villoro, C. Scheu, S. Zhang, et al. (2023) Composite design of half-Heusler thermoelectrics: Selective doping of grain boundary phases in NbFeSb by InSb, Materials Today Physics 38, 101240 – DOI: https://doi.org/10.1016/j.mtphys.2023.101240
[5] K.N. Sasidhar, H. Khanchandani, S. Zhang, et al. (2023) Understanding the protective ability of the native oxide on an Fe-13 at. % Cr alloy at the atomic scale: A combined atom probe and electron microscopy study, Corrosion Science 211, 110848 – DOI: https://doi.org/10.1016/j.corsci.2022.110848
[6] D. Neuß, I.E. McCarroll, S. Zhang, et al. (2024) High-resolution chemical and structural characterization of the native oxide scale on a Mg-based alloy, Corrosion Science 227, 111776 – DOI: https://doi.org/10.1016/j.corsci.2023.111776
[7] W. Luo, Z. Xie, S. Zhang, et al. (2023) Tailoring the Plasticity of Topologically Close‐packed Phases via the Crystals’ Fundamental Building Blocks, Advanced Materials 35, 2300586 – DOI: https://doi.org/10.1002/adma.202300586
[8] M. Zubair, M. Felten, S. Zhang, et al. (2023) Laves phases in Mg-Al-Ca alloys and their effect on mechanical properties, Materials & Design 225, 111470 – DOI: https://doi.org/10.1016/j.matdes.2022.111470
[9] A.S.A. Alhassan, S. Zhang, B. Berkels (2023) Direct motif extraction from high resolution crystalline STEM images, Ultramicroscopy 254, 113827 – DOI: https://doi.org/10.1016/j.ultramic.2023.113827