Dislocation core field. II. Screw dislocation in iron

TL;DR

This paper investigates the dislocation core field of <111> screw dislocations in alpha-iron, revealing its significance for accurate atomistic simulation analysis and dislocation interactions.

Contribution

It characterizes the dislocation core field in iron using ab initio calculations and models its effects within anisotropic linear elasticity.

Findings

Core field corresponds to biaxial dilatation

Core field affects dislocation interaction energies

Consideration of core field improves quantitative analysis

Abstract

The dislocation core field, which comes in addition to the Volterra elastic field, is studied for the <111> screw dislocation in alpha-iron. This core field, evidenced and characterized using ab initio calculations, corresponds to a biaxial dilatation, which we modeled within the anisotropic linear elasticity. We show that this core field needs to be considered when extracting quantitative information from atomistic simulations, such as dislocation core energies. Finally, we look at how dislocation properties are modified by this core field, by studying the interaction between two dislocations composing a dipole, as well as the interaction of a screw dislocation with a carbon atom.