Dislocation Core Energies and Core Fields from First Principles

Emmanuel Clouet (1, 2) , Lisa Ventelon (1) , François Willaime (1)

1 SRMP - Service de recherches de métallurgie physique
2 LMPGM - Laboratoire de Métallurgie Physique et Génie des Matériaux

Ab initio calculations in bcc iron show that a <111> screw dislocation induces a short-range dilatation field in addition to the Volterra elastic field. This core field is modeled in anisotropic elastic theory using force dipoles. The elastic modeling thus better reproduces the atom displacements observed in ab initio calculations. Including this core field in the computation of the elastic energy allows deriving a core energy which converges faster with the cell size, thus leading to a result which does not depend on the geometry of the dislocation array used for the simulation.

Mots clés: Dislocation; screw; elasticity; core; ab initio; Fe

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Emmanuel Clouet, Lisa Ventelon, François Willaime. Dislocation Core Energies and Core Fields from First Principles. Physical Review Letters, 2009, 102 (5), pp.055502. ⟨hal-00359884⟩