  Using large-scale atomistic simulations, dislocation mechanics in the
presence of linear complexions are investigated in an Fe-Ni alloy, where the
complexions appear as nanoparticle arrays along edge dislocation lines. When
mechanical shear stress is applied to drive dislocation motion, a strong
pinning effect is observed where the defects are restricted by their own linear
complexion structures. This pinning effect becomes weaker after the first
dislocation break-away event, leading to a stress-strain curve with a profound
initial yield point, similar to the static strain ageing behavior observed
experimentally for Fe-Mn alloys with the same type of linear complexions. The
existence of such a response can be explained by local diffusion-less and
lattice distortive transformations corresponding to L10-to-B2 phase transitions
within the linear complexion nanoparticles. As such, an interdependence between
linear complexion structure and dislocation mechanics is found.
