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M: Metallphysik

M 32: Poster TU B (Symposium Tomographic Methods in Materials Research M-32.32-55)

M 32.20: Poster

Montag, 7. März 2005, 14:30–16:30, Poster TU B

Molecular dynamics simulation of aluminium diffusion in decagonal quasicrystals — •Stephen Hocker and Franz Gähler — Universität Stuttgart, Institut für theoretische und angewandte Physik, 70550 Stuttgart

Aluminium diffusion in decagonal Al-Ni-Co and Al-Cu-Co quasicrystals is investigated by molecular dynamics simulations, using newly generated EAM potentials. As in our previous work with classical effective pair potentials, above two thirds of the melting temperature strong aluminium diffusion is observed. Compared to pair potentials, the diffusivities in the decagonal plane are enhanced, which is attributed to additional diffusion processes. Furthermore, with EAM potentials the transition metal atoms are more mobile, so that their diffusion is also measurable. The activation enthalpies and the activation volumes are determined by measuring the diffusivities as a function of temperature and pressure. The qualitative behavior of the dynamics is confirmed by ab-initio simulations.