Influence of strain on dislocation core in silicon. Issue 13 (3rd May 2018)

• Record Type: Journal Article
• Authors: Pizzagalli, L.; Godet, J.; Brochard, S.
• Is Part Of: Philosophical magazine. Volume 98:Issue 13(2018)
• Page Start: 1151
• Page End: 1169
• Publication Date: 2018-05-03
• Subjects: Dislocations -- silicon -- strain -- density functional theory -- tight binding -- interatomic potential; Condensed matter -- Periodicals; Physics -- Periodicals; Matière condensée -- Périodiques; Physique -- Périodiques; 530.41
• DOI: 10.1080/14786435.2018.1431412
• Languages: English
• ISSNs: 1478-6435

Abstract

Abstract: First principles, density functional-based tight binding and semi-empirical interatomic potentials calculations are performed to analyse the influence of large strains on the structure and stability of a 60 dislocation in silicon. Such strains typically arise during the mechanical testing of nanostructures like nanopillars or nanoparticles. We focus on bi-axial strains in the plane normal to the dislocation line. Our calculations surprisingly reveal that the dislocation core structure largely depends on the applied strain, for strain levels of about 5%. In the particular case of bi-axial compression, the transformation of the dislocation to a locally disordered configuration occurs for similar strain magnitudes. The formation of an opening, however, requires larger strains, of about 7.5%. Furthermore, our results suggest that electronic structure methods should be favoured to model dislocation cores in case of large strains whenever possible.