It was recalled that a dislocation which moved through a quasi-crystal left, in its wake, a fault that was referred to as a phason wall. The disregistry energy of this wall was studied, for a 2-dimensional model quasi-crystal, in order to determine possible Burgers vectors of the quasi-crystalline structure. It was noted that, unlike the case of periodic crystals, the disregistry energy was an average quantity; with large fluctuations at the atomic scale. The dislocation core structure and mobility could therefore not be linked to this quantity by, for instance, a Peierls-Nabarro model. Atomistic simulations showed that dislocation motion was controlled by local obstacles which were inherent to the atomic structure of the quasi-crystal.

Dislocations in Quasicrystals and their Interaction with Cluster-Like Obstacles R.Mikulla, P.Gumbsch, H.R.Trebin: Philosophical Magazine Letters, 1998, 78[5], 369-76