The electronic effect of N impurity in an < 100 > edge dislocation core system in alpha-iron

Citation
Y. Niu et al., The electronic effect of N impurity in an < 100 > edge dislocation core system in alpha-iron, COMP MAT SC, 22(3-4), 2001, pp. 144-150
Citations number
35
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
COMPUTATIONAL MATERIALS SCIENCE
ISSN journal
0927-0256 → ACNP
Volume
22
Issue
3-4
Year of publication
2001
Pages
144 - 150
Database
ISI
SICI code
0927-0256(200112)22:3-4<144:TEEONI>2.0.ZU;2-D
Abstract
First-principles methods are employed to investigate the structure relaxati on and the electronic structure of a N impurity in an (100) edge dislocatio n core (DC) system in alpha -iron. A 96-atom cluster model is used to simul ate the local environment of N impurity in the edge dislocation. By use of the DMol method, we obtained an optimized atomic configuration for the syst em by calculating the forces on N impurity and its neighboring Fe atoms, an d by minimizing the total energy of the cluster model. The optimization res ults show that the N impurity moves away from compression region to a stabl e position in the dilated region. By use of the discrete variational (DV) m ethod, we calculated energetic parameters (structural energy and interatomi c energy) and charge distribution. From these results, one can find that N impurity has a strong interaction with its adjacent Fe atoms in the DC syst em. Moreover, notable charge redistribution between the N impurity and Fe a toms indicates the formation of N impurity-Fe dislocation complex, which im plies the trapping effect of DC on N impurity. (C) 2001 Elsevier Science B. V. All rights reserved.