Figure 7: Deformation evolution of Cu(1 1 19) deformed in compression.

(a) Defects nucleate at the steps on the surface. (b) Parallel twins grow into the bulk along the direction of the active slip system. (c) Twins remain the prevailing deformation mechanism, the perpendicular slip system is not activated. Atoms comprising surfaces and stacking faults are shown, others (CS < 2) are removed for clarity.