A new modification of the formulation of Peierls stress

Abstract The classical derivation of Peierls stress is critically examined. It is found that in Peierls-Nabbaro treatments there may exist an error in representing the atom positions across the slip plane after the dislocation is assumed to be translated by a distance. With the correction of this error, it is shown that the misfit energy of the dislocation and the lattice friction to dislocation motion have an expected periodicity of the Burgers vector b rather than the unexpected periodicity of b 2 predicted by the original model. Under the new representations of atom positions, it is also shown that the Peierls stress formula for a dislocation in a lattice in which atoms just above and below the slip plane face each other may not be different from that for a dislocation in a lattice in which atoms alternate across the slip plane, as suggested before.