Defect nucleation from a pre-existing intrinsic I1 stacking fault in magnesium by molecular dynamics simulations

[Display omitted] •Defect nucleation in the vicinity of an I1 SF in Mg was investigated.•MD simulations containing an I1 SF under simple shear were carried out.•Depending on stress states, the observed behaviors clearly varied.•c+a partial dislocations were generated from the side ends of the I1 SF. In order to clarify defect nucleation in the vicinity of a pre-existing intrinsic I1 stacking fault (SF) in magnesium (Mg), we carried out molecular dynamics (MD) simulations containing an I1 SF under several applied shear stresses, using a modified embedded atom method (MEAM) potential. Depending on stress states, different types of defects were generated from the I1 SF. Under shear stress on 0001 basal plane along 112¯0 direction, 112¯1 twin was formed from the side ends of the I1 SF. On the other hand, in the case of higher resolved shear stress (RSS) for c+a pyramidal slips, c+a partial dislocations were generated with SFs on the first-pyramidal planes as well as the second-pyramidal planes. The dissociation reactions of the dislocations at the side ends of the I1 SF were energetically evaluated, and it was implied that nucleation of the c+a dislocations on the first-pyramidal planes is more favorable than on the second-pyramidal planes. These results suggest that I1 SFs are attractive defects for nucleation of c+a dislocations.