The Peierls stress of the moving ½<111>{110} screw dislocation with a planar and non-dissociated core structure in Ta was calculated. The elastic strain energy which was associated with the discrete effect of the lattice and ignored in classical Peierls–Nabarro (P–N) theory was taken into account in calculating the Peierls stress, and it could make the Peierls stress become smaller. The Peierls stress obtained was very close to the experimental data. As shown in the numerical calculations and atomistic simulations, the core structure of the screw dislocation undergoes significant changes under the explicit stress before the screw dislocation moves. Moreover, the mechanism of the screw dislocation was revealed by these results and the experimental data that the screw dislocation retracts its extension in three {110} planes and transforms its dissociated core structure into a planar configuration. Therefore, the core structure of the moving ½<111>{110} screw dislocation in Ta was proposed to be planar.

The Peierls Stress of the Moving ½<111>{110} Screw Dislocation in Ta. R.Liu, S.Wang, X.Wu: Journal of Physics - Condensed Matter, 2009, 21[34], 345401