The transition from the behavior of a single dislocation interacting with a field of fixed obstacles to the collective motion of multiple dislocations was studied below the de-pinning transition (thermally activated glide). In absence of interactions, a truncated power law distribution of jump amplitudes (avalanches) with a diverging cut-off toward the critical point, and intermittency were observed. Interactions lead to a modification of the correlation length exponent below the critical point and to more pronounced intermittency, a dynamics more compatible to acoustic emission experimental data.

Dynamics below the Depinning Transition of Interacting Dislocations Moving over Fields of Obstacles. R.Li, R.C.Picu, J.Weiss: Physical Review E, 2010, 82[2], 022107