  Active room temperature diffusion-less climb of the <a> edge dislocations in
model Mg-Al alloys was observed using molecular dynamics simulations.
Dislocations on prismatic and pyramidal I planes climb through the basal plane
to overcome solute obstacles. This out-of-plane dislocation motion softens the
high resistance pyramidal I glide and significantly reduces the anisotropy of
dislocation mobility, and could help improve the ductility of Mg. The flow
stress scales linearly with solute concentration, cAl. Dislocations climb
predominantly in the negative direction, with climb angle on the order of
0.01cAl, producing very high vacancy concentration on the order of 10-4.
