⟨110⟩{111} dislocation core properties in L12 Al3Sc and Al3Mg based on the Peierls-Nabarro model

The generalized stacking fault (GSF) energy curves along the 110 direction on {111} slip plane for L1(2) Al3Sc and Al3Mg are calculated within the framework of density functional theory (DFT), and anti-phase boundary (APB) energies are obtained. Then the structures and properties of collinear dissociated 110{111} dislocations in Al3Sc and Al3Mg are studied using Peierls-Nabarro (PN) model combined with GSF energies, the obtained dislocation dissociation width of the 110{111} edge dislocation in Al3Sc is in agreement with the available experimental value. In comparison with Al3Mg, the dislocation dissociation widths of both screw and edge in Al3Sc are narrower and the Peierls energies and stresses are lower, while the core energies are much higher. Furthermore, for both Al3Sc and Al3Mg, the core energy of screw dislocation is smaller than that of edge dislocation, while the Peierls energy and stress of screw dislocation is slightly larger. (C) 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim