Peierls barriers and stresses for edge dislocations in Pd and Al calculated from first principles

Abstract
We report generalized stacking fault (GSF) curves along the [121] and [110] directions for Pd and Al, calculated from first principles. The GSF curves are applied in the classic PN model to calculate Peierls barriers and stresses for the Shockley partials and the unsplit edge dislocations in Pd and Al. The obtained stresses using relaxed GSF curves agree well with experiments. The numerical results are also compared with a recently derived analytical expression for the Peierls stress. The GSF curves have been calculated with a pseudopotential implementation of density functional theory. The accuracy of the method have been tested by calculating values for various stacking fault energies of Al, Ni, Cu, Ag, and Pd which favorably compare with other theoretical and experimental values.