SKM 2023 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 12: Poster I

MM 12.16: Poster

Montag, 27. März 2023, 18:15–20:00, P2/OG1+2

DFT structural characterization of β- and δ- intermetallic Al-Fe-Si phases — •Nebahat Bulut¹, Hanka Becker², Andreas Leineweber², and Jens Kortus¹ — ¹TU Bergakademie Freiberg, Institute of Theoretical Physics, Germany — ²TU Bergakademie Freiberg, Institute of Materials Science, Germany

The β-Al_4.5FeSi and δ-Al₃FeSi₂ phases are known stable phases of Fe-containing hypoeutectuc Al-Si alloys. Despite the known stoichiometry of the β- and δ- phase the positions of the Al and Si atoms in these Al-Fe-Si intermetallic phases could not be uniquely determined experimentally. Therefore possible positions of Si atoms in these intermetallic phases were investigated using the density functional theory (DFT) code Quantum Espresso, which is based on plane waves and pseudopotentials [2]. For both β- and δ- phase different arrangements of Si atoms in the Al-Fe-Si intermetallics were considered. We compare the energies of these arrangements (1) relaxing the atomic positions keeping the unit cell volume constant and (2) fully relaxing atomic positions and unit cell shape and volume. As result we find that arrangements where the Si atoms are not nearest neighbours are energetically favored [2]. Further, we analyze the electronic structure and investigate the bonding.
[1] P. Giannozzi et al., J.Phys.Condens.Matter 21, 395502 (2009)
[2] Becker et al. J. Alloys and Comp. 911 (2022) 165015