Elastic and Core Anisotropies for the 〈111〉 Screw Dislocation in Cubic Crystals

Abstract

The stress component s̀rz which gives rise to an angular force between parallel screw dislocations is calculated. The stress components tend to stabilize a pile‐up of screws on a {112} plane, while they would add to the instability of pile‐ups on {110} planes. Sodium is an extreme case in which a pile‐up on {112} should be elastically stable so that it cannot disperse by cross‐slip. It is also demonstrated that in general there are asymmetries in the dislocation cores, which are manifested as important asymmetries in dislocation mobility and cross‐slip processes.