Nonequilibrium configurations and peierls potential of screw dislocations in the b.c.c. lattice

A model for the calculation of the Peierls potential of straight screw dislocations in the b.c.c. lattice is developed. The method takes into account the detailed atomic nonequilibrium structure of the dislocation. Those nonequilibrium configurations which play a leading part during the dislocation motion have been classified by two core‐structure parameters, which can be regarded as “generalized dislocation position”. The Peierls potential, i.e. the dislocation energy as a function of these parameters, has been calculated. The equipotential contours of the Peierls potential and the saddle‐point configurations of screw dislocations are presented, and several types of the dislocation motion are discussed. Further, the influence of external stress has been analyzed. It turns out that the macroscopic slip of screw dislocations is composed of elementary {110} slip processes.