title: Nodal effects in dislocation mobility.
abstract: We show that, contrary to the prevailing perception, dislocations can become more mobile by zipping together to form junctions. In a series of direct atomistic simulations, the critical stress to move a junction network in a [110] plane of bcc molybdenum is found to be always smaller ( approximately 50%) than that required to move isolated dislocations. Our data support a previously proposed hypothesis about the nature of anomalous slip in bcc transition metals, yet offer a different atomistic mechanism for conservative motion of screw dislocation networks. The same data suggest a hierarchy of motion mechanisms in which lower-dimensional crystal imperfections control the rate of sliding along the low-angle twist boundaries.
authors.affiliation: Lawrence Livermore National Laboratory, University of California, Livermore, California 94550, USA.
authors.forename: Vasily V
authors.initials: VV
authors.lastname: Bulatov
authors.forename: Wei
authors.initials: W
authors.lastname: Cai