Core structures and mobility of ⟨c⟩ dislocations in magnesium

The core structures and mobility of < c > dislocations in magnesium were predicted using both density functional theory and molecular dynamics simulations. The pure edge and screw cores are compact at 0 K. With increasing temperature up to 700 K, the edge dislocation dissociates into two < c >/2 partials on the basal plane, but remains immobile. The screw dislocation remains compact and continuously cross-slips between the three prismatic planes. At room temperature, the screw dislocation only glides after emitting a vacancy at 420 MPa. The Peierls stress of the dislocation after vacancy emission is 50 MPa. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.