Correlation functions and the dynamical structure factor of quasicrystals
Institut für Theoretische und Angewandte Physik,
Pfaffenwaldring 57, 70550 Stuttgart,
Revised: 8 June 2000
Published online: 15 October 2000
The icosahedral or decagonal symmetry of quasicrystals is well described by a periodic structure in higher dimensions. One consequence is the existence of dynamic phason modes in addition to the phonon modes. In an atomistic model phasons show up as correlated atomic jumps. We detect the phasons by the calculation of correlation functions and the dynamical structure factor in molecular dynamics simulations similar to the procedure used for phonons. In the simulations it is also possible to observe atomic jump processes directly. The models studied here represent icosahedral AlCuLi and decagonal AlCuCo quasicrystals. Ring processes are observed in the icosahedral case, and flips in the decagonal model.
PACS: 61.44.Br – Quasicrystals / 66.30.-h – Diffusion in solids / 68.45.Kg – Dynamics; vibrations
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2000