Edge dislocation core structures in FCC metals determined fromab initiocalculations combined with the improved Peierls–Nabarro equation

We have employed the improved Peierls–Nabarro (P–N) equation to study the properties of 1/2⟨110⟩ edge dislocation in the {111} plane in face-centered cubic (FCC) metals Al, Cu, Ir, Pd and Pt. The generalized-stacking-fault energy surface entering the equation is calculated by using first-principles density functional theory (DFT). The accuracy of the method has been tested by calculating the values for various stacking fault energies that favorably compare with previous theoretical and experimental results. The core structures, including the core widths of the edge and screw components, and dissociation behavior have been investigated. The dissociated distance between two partials for Al in our calculation agrees well with the values obtained from numerical simulation with DFT and molecular dynamics simulation, as well as experiment. Our calculations show that it is preferred to create partial dislocations in Cu, and easily observed full dislocations in Al, Ir, Pd and especially Pt.