Dislocation kinetics in quasicrystals under small applied stress

The sliding of dislocations in quasicrystals under small applied stress is considered within phenomenological model. Implications of the quasi-periodic Peierls potential for the dislocation pinning is analyzed and associated activation mechanism is shown to be relevant for the plastic deformation of quasicrystals. The dependence of the dislocation velocity and strain rate on the applied stress is estimated. Kinetics of the dislocation movement in the quasi-periodic pinning potential is analyzed in exactly solvable one-dimensional model. The spectrum of the dislocation jump lengths is found to be a universal function of applied stress. The critical values of resolved stress leading to the drastic changes in the dislocation velocity are shown to form periodical sequence in a logarithm scale. Recent experiments on the mechanical properties of quasicrystals are discussed within proposed model.