Structure, Energetics, and Dynamics of Screw Dislocations in Even n-Alkane Crystals

Spiral hillocks on n-alkane crystal surfaces were observed immediately after Frank recognized the importance of screw dislocations for crystal growth, yet their structures and energies in molecular crystals remain ill-defined. To illustrate the structural chemistry of screw dislocations that are res...

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Main Authors: Olson, I., Shtukenberg, A., Hakobyan, G., Rohl, Andrew, Raiteri, Paolo, Ward, M., Kahr, B.
Format: Journal Article
Published: American Chemical Society 2016
Online Access:http://purl.org/au-research/grants/arc/DP140101776
http://hdl.handle.net/20.500.11937/40005
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author Olson, I.
Shtukenberg, A.
Hakobyan, G.
Rohl, Andrew
Raiteri, Paolo
Ward, M.
Kahr, B.
author_facet Olson, I.
Shtukenberg, A.
Hakobyan, G.
Rohl, Andrew
Raiteri, Paolo
Ward, M.
Kahr, B.
author_sort Olson, I.
building Curtin Institutional Repository
collection Online Access
description Spiral hillocks on n-alkane crystal surfaces were observed immediately after Frank recognized the importance of screw dislocations for crystal growth, yet their structures and energies in molecular crystals remain ill-defined. To illustrate the structural chemistry of screw dislocations that are responsible for plasticity in organic crystals and upon which the organic electronics and pharmaceutical industries depend, molecular dynamics was used to examine heterochiral dislocation pairs with Burgers vectors along [001] in n-hexane, n-octane, and n-decane crystals. The cores were anisotropic and elongated in the (110) slip plane, with significant local changes in molecular position, orientation, conformation, and energy. This detailed atomic level picture produced a distribution of strain consistent with linear elastic theory, giving confidence in the simulations. Dislocations with doubled Burgers vectors split into pairs with elementary displacements. These results suggest a pathway to understanding the mechanical properties and failure associated with elastic and plastic deformation in soft crystals.
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institution Curtin University Malaysia
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publishDate 2016
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spelling curtin-20.500.11937-400052022-10-12T02:59:59Z Structure, Energetics, and Dynamics of Screw Dislocations in Even n-Alkane Crystals Olson, I. Shtukenberg, A. Hakobyan, G. Rohl, Andrew Raiteri, Paolo Ward, M. Kahr, B. Spiral hillocks on n-alkane crystal surfaces were observed immediately after Frank recognized the importance of screw dislocations for crystal growth, yet their structures and energies in molecular crystals remain ill-defined. To illustrate the structural chemistry of screw dislocations that are responsible for plasticity in organic crystals and upon which the organic electronics and pharmaceutical industries depend, molecular dynamics was used to examine heterochiral dislocation pairs with Burgers vectors along [001] in n-hexane, n-octane, and n-decane crystals. The cores were anisotropic and elongated in the (110) slip plane, with significant local changes in molecular position, orientation, conformation, and energy. This detailed atomic level picture produced a distribution of strain consistent with linear elastic theory, giving confidence in the simulations. Dislocations with doubled Burgers vectors split into pairs with elementary displacements. These results suggest a pathway to understanding the mechanical properties and failure associated with elastic and plastic deformation in soft crystals. 2016 Journal Article http://hdl.handle.net/20.500.11937/40005 10.1021/acs.jpclett.6b01459 http://purl.org/au-research/grants/arc/DP140101776 http://purl.org/au-research/grants/arc/FT130100463 American Chemical Society fulltext
spellingShingle Olson, I.
Shtukenberg, A.
Hakobyan, G.
Rohl, Andrew
Raiteri, Paolo
Ward, M.
Kahr, B.
Structure, Energetics, and Dynamics of Screw Dislocations in Even n-Alkane Crystals
title Structure, Energetics, and Dynamics of Screw Dislocations in Even n-Alkane Crystals
title_full Structure, Energetics, and Dynamics of Screw Dislocations in Even n-Alkane Crystals
title_fullStr Structure, Energetics, and Dynamics of Screw Dislocations in Even n-Alkane Crystals
title_full_unstemmed Structure, Energetics, and Dynamics of Screw Dislocations in Even n-Alkane Crystals
title_short Structure, Energetics, and Dynamics of Screw Dislocations in Even n-Alkane Crystals
title_sort structure, energetics, and dynamics of screw dislocations in even n-alkane crystals
url http://purl.org/au-research/grants/arc/DP140101776
http://purl.org/au-research/grants/arc/DP140101776
http://hdl.handle.net/20.500.11937/40005