Computer simulation of Peierls stress by using lattice statics Green's function

The Peierls stress τ_P is calculated for a discrete lattice model with changing the geometrical factor of the crystal h/b, where h is the spacing of the slip plane and b is the Burgers vector. Unlike the continuum model where a continuous distribution of the infinitesimal dislocation is assumed, the Peierls stress is determined as the critical applied stress beyond which no stable configuration of dislocation is found. The positions of atoms are calculated by the lattice statics Green's function. The results for the lattice model are well approximated by the exponential relation, τ_P/G ∼ exp(-Ah/b), as predicted by the continuum model, where G is the shear modulus. The Peierls stresses for some interatomic potentials are slightly lower than those obtained from experiments. The period of the Peierls potential derived from the lattice model is b, which is identical to the lattice constant.