Bias factor of dislocation loops in quasicrystalline materials

Vacancy swelling of quasicrystals under irradiation is considered. In quasicrystals, the evolution of dislocations is accompanied by the formation of phasons which are localized topological defects of the vacancy and interstitial types. At moderate temperatures the diffusivity of phasons is low which leads to the formation of ring-or disk-shaped phason trails inside dislocation loops. To find the capture efficiency of point defects by a dislocation loop with the complementary ring of phasons the steady-state drift-diffusional problem is solved in the toroidal geometry by the successive overrelaxation method. It is shown that phasons significantly reduce the bias of dislocations towards absorption of interstitial atoms. For this reason, quasicrystalline materials are predicted to exhibit increased resistance to vacancy swelling.