Core Energies in Isolated Edge and Mixed Dislocations in BCC Fe from First-principles Energy Density Method

Fuente: arXiv
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Main Authors: Dan, Yang, Trinkle, Dallas R.
Format: Preprint
Published: 2025
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author Dan, Yang
Trinkle, Dallas R.
author_facet Dan, Yang
Trinkle, Dallas R.
contents We use first-principles spin-polarized energy density method (EDM) to calculate the atomic energies in isolated $a_0[100](010)$ edge, $a_0[100](011)$ edge, $\frac{a_0}{2}[\bar1\bar11](1\bar10)$ edge and $\frac{a_0}{2}[111](1\bar10)$ $71^\circ$ mixed dislocations in body-centered cubic (BCC) Fe. The distribution of atomic energies shows the energetic effects of slip, including non-linear displacements in and near the core, and the elastic field further away. The EDM atomic energies agree well with anisotropic elasticity predictions in the elastic region, while they deviate in the core region due to failure of linear elasticity, and the energy deviation quantifies the core widths. Dislocation line energies are obtained by partial sums of the atomic energies within distance $r$ of the dislocation center; the core energy is extracted from the large $r$ behavior. We compare our results with an EAM and a GAP potential, showing that while both potentials produce core structures similar to DFT predictions, the GAP potential has a closer match with DFT and EDM in core energies.
format Preprint
id arxiv_https___arxiv_org_abs_2503_10776
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Core Energies in Isolated Edge and Mixed Dislocations in BCC Fe from First-principles Energy Density Method
Dan, Yang
Trinkle, Dallas R.
Materials Science
We use first-principles spin-polarized energy density method (EDM) to calculate the atomic energies in isolated $a_0[100](010)$ edge, $a_0[100](011)$ edge, $\frac{a_0}{2}[\bar1\bar11](1\bar10)$ edge and $\frac{a_0}{2}[111](1\bar10)$ $71^\circ$ mixed dislocations in body-centered cubic (BCC) Fe. The distribution of atomic energies shows the energetic effects of slip, including non-linear displacements in and near the core, and the elastic field further away. The EDM atomic energies agree well with anisotropic elasticity predictions in the elastic region, while they deviate in the core region due to failure of linear elasticity, and the energy deviation quantifies the core widths. Dislocation line energies are obtained by partial sums of the atomic energies within distance $r$ of the dislocation center; the core energy is extracted from the large $r$ behavior. We compare our results with an EAM and a GAP potential, showing that while both potentials produce core structures similar to DFT predictions, the GAP potential has a closer match with DFT and EDM in core energies.
title Core Energies in Isolated Edge and Mixed Dislocations in BCC Fe from First-principles Energy Density Method
topic Materials Science
url https://arxiv.org/abs/2503.10776