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Size effects and strain localization in atomic-scale cleavage modeling
Publikationstyp
Journal Article
Date Issued
2015-07-29
Sprache
English
Author(s)
TORE-URI
Volume
27
Issue
34
Article Number
345002
Citation
Journal of Physics Condensed Matter 34 (27): 345002 (2015)
Publisher DOI
Scopus ID
Publisher
IOP Publ.
In this work, we study the adhesion and decohesion of Cu(1 0 0) surfaces using density functional theory (DFT) calculations. An upper stress to surface decohesion is obtained via the universal binding energy relation (UBER), but the model is limited to rigid separation of bulk-terminated surfaces. When structural relaxations are included, an unphysical size effect arises if decohesion is considered to occur as soon as the strain energy equals the energy of the newly formed surfaces. We employ the nudged elastic band (NEB) method to show that this size effect is opposed by a size-dependency of the energy barriers involved in the transition. Further, we find that the transition occurs via a localization of bond strain in the vicinity of the cleavage plane, which resembles the strain localization at the tip of a sharp crack that is predicted by linear elastic fracture mechanics.
Subjects
cleavage
density functional theory (DFT)
localization
size effects
uniaxial tension
DDC Class
500: Naturwissenschaften