It was shown that dislocations could become more mobile by zipping together to form junctions. In a series of atomistic simulations, the critical stress required to move a junction network in a {110} plane of body-centered cubic Mo was always smaller (about 50%) than that required to move isolated dislocations. The present data supported a previous hypothesis concerning the nature of anomalous slip in body-centered cubic transition metals, but offered a different atomistic mechanism for the conservative motion of screw dislocation networks. The same data suggested the existence of a hierarchy of mechanisms in which lower-dimensional crystal imperfections controlled the rate of sliding along the low-angle twist boundaries.

Nodal Effects in Dislocation Mobility. V.V.Bulatov, W.Cai: Physical Review Letters, 2002, 89[11], 115501 (4pp)