Abstract
We extend the Peierls-Nabarro (PN) model to eliminate the "continuum" approximation for the misfit energy, and use it to analyze features of the evolution of the dislocation core structure under various stress conditions (glide and Escaig stress). We show that the core may assume competing multiple structures with their marked dependence on the dislocation axis position. As we demonstrate for ordinary dislocations in fee Ir and the ordered L1o CuAu calculated using ab-initio generalized stacking fault energies, these lattice discreteness effects, missing in the original PN model, significantly affects the evolution of the dislocation under stress. In particular, these effects may result in the ladder-like dependence of the partial separation under Escaig stress conditions, and dramatic changes in the shape and amplitude of the Peierls barrier. Thus, we find that lattice discreteness effects can be significant not only in ordered alloys with a deep Peierls valley but also in fee metals under stress and further, these effects result in the evolution of dislocation structure which is more complex than previously thought.
| Original language | English |
|---|---|
| Pages (from-to) | 138-141 |
| Number of pages | 4 |
| Journal | Materials Science and Engineering A |
| Volume | 309-310 |
| DOIs | |
| Publication status | Published - Jul 15 2001 |
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Keywords
- Dislocation
- Misfit energy
- Parameterization
ASJC Scopus subject areas
- Materials Science(all)
Cite this
Complex evolution of dislocation core structure in a process of motion : Model analysis with ab-initio parameterization. / Mryasov, O. N.; Gornostyrev, Yu N.; Van Schilfgaarde, M.; Freeman, Arthur J.
In: Materials Science and Engineering A, Vol. 309-310, 15.07.2001, p. 138-141.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Complex evolution of dislocation core structure in a process of motion
T2 - Model analysis with ab-initio parameterization
AU - Mryasov, O. N.
AU - Gornostyrev, Yu N.
AU - Van Schilfgaarde, M.
AU - Freeman, Arthur J
PY - 2001/7/15
Y1 - 2001/7/15
N2 - We extend the Peierls-Nabarro (PN) model to eliminate the "continuum" approximation for the misfit energy, and use it to analyze features of the evolution of the dislocation core structure under various stress conditions (glide and Escaig stress). We show that the core may assume competing multiple structures with their marked dependence on the dislocation axis position. As we demonstrate for ordinary dislocations in fee Ir and the ordered L1o CuAu calculated using ab-initio generalized stacking fault energies, these lattice discreteness effects, missing in the original PN model, significantly affects the evolution of the dislocation under stress. In particular, these effects may result in the ladder-like dependence of the partial separation under Escaig stress conditions, and dramatic changes in the shape and amplitude of the Peierls barrier. Thus, we find that lattice discreteness effects can be significant not only in ordered alloys with a deep Peierls valley but also in fee metals under stress and further, these effects result in the evolution of dislocation structure which is more complex than previously thought.
AB - We extend the Peierls-Nabarro (PN) model to eliminate the "continuum" approximation for the misfit energy, and use it to analyze features of the evolution of the dislocation core structure under various stress conditions (glide and Escaig stress). We show that the core may assume competing multiple structures with their marked dependence on the dislocation axis position. As we demonstrate for ordinary dislocations in fee Ir and the ordered L1o CuAu calculated using ab-initio generalized stacking fault energies, these lattice discreteness effects, missing in the original PN model, significantly affects the evolution of the dislocation under stress. In particular, these effects may result in the ladder-like dependence of the partial separation under Escaig stress conditions, and dramatic changes in the shape and amplitude of the Peierls barrier. Thus, we find that lattice discreteness effects can be significant not only in ordered alloys with a deep Peierls valley but also in fee metals under stress and further, these effects result in the evolution of dislocation structure which is more complex than previously thought.
KW - Dislocation
KW - Misfit energy
KW - Parameterization
UR - http://www.scopus.com/inward/record.url?scp=17744419419&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=17744419419&partnerID=8YFLogxK
U2 - 10.1016/S0921-5093(00)01710-X
DO - 10.1016/S0921-5093(00)01710-X
M3 - Article
VL - 309-310
SP - 138
EP - 141
JO - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
JF - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
SN - 0921-5093
ER -