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MM: Fachverband Metall- und Materialphysik
MM 12: Poster I
MM 12.16: Poster
Monday, March 27, 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-Al4.5FeSi 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