It was recalled that, at low temperatures, the dynamics of amorphous material involved a sequence of discrete activated events that locally reorganized the topological network. By using activation-relaxation techniques, a database of over 8000 such events was generated, and the latter were analyzed with regard to their energy barriers and asymmetry, displacement and volume expansion or contraction. Special attention was paid to events which corresponded to diffusing coordination defects. The energetics were not clearly related to displacements, nor to the defect densities in fully relaxed configurations. However, some relationship to the local volume expansion was found in that it tended to increase by about 4eV per Å3. The topological properties of the events were unexpectedly varied.

Activated Mechanisms in Amorphous Silicon - an Activation-Relaxation Technique Study N.Mousseau, G.T.Barkema: Physical Review B, 2000, 61[3], 1898-906