Molecular dynamics simulation of aluminium diffusion in decagonal quasicrystals

A1 diffusion in decagonal Al-Ni-Co and Al-Cu-Co quasicrystals is investigated by molecular dynamics simulations. Results obtained with newly developed embedded-atom method potentials are compared with our previous work with effective pair potentials. With both types of potential, strong aluminium diffusion is observed above two-thirds of the melting temperature, and the general behaviours of the system are quite similar. The diffusion constant is measured as a function of temperature and pressure, and the activation enthalpies and activation volumes are determined from the resulting Arrhenius plot. For a number of important diffusion processes, the energy barriers are determined with molecular statics simulations. The qualitative behaviour of the dynamics is also confirmed by ab-initio simulations.