Prediction of Peierls stresses for different crystals

It is a long outstanding question whether or not the Peierls stress for a given slip system of a crystal can be quantitatively determined. This paper concerns the prediction of this stress for a wide range of crystals, using a new theoretical Peierls stress equation. It is shown that the prediction is in reasonable agreement with experimental data. Comparison with atomistic calculations illustrates that the accuracy of the prediction may degenerate greatly in the cases where the spreading of the dislocation core is non-planar and the application of an external stress changes the core structure significantly. It is suggested that the magnitude of the Peierls stress is determined primarily by the geometrical configuration of the dislocation core.