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Assessment of interatomic potentials for atomistic analysis of static and dynamic properties of screw dislocations in W.
J Phys Condens Matter 2013; 25(8):085702JP

Abstract

Screw dislocations in bcc metals display non-planar cores at zero temperature which result in high lattice friction and thermally-activated strain rate behavior. In bcc W, electronic structure molecular statics calculations reveal a compact, non-degenerate core with an associated Peierls stress between 1.7 and 2.8 GPa. However, a full picture of the dynamic behavior of dislocations can only be gained by using more efficient atomistic simulations based on semiempirical interatomic potentials. In this paper we assess the suitability of five different potentials in terms of static properties relevant to screw dislocations in pure W. Moreover, we perform molecular dynamics simulations of stress-assisted glide using all five potentials to study the dynamic behavior of screw dislocations under shear stress. Dislocations are seen to display thermally-activated motion in most of the applied stress range, with a gradual transition to a viscous damping regime at high stresses. We find that one potential predicts a core transformation from compact to dissociated at finite temperature that affects the energetics of kink-pair production and impacts the mechanism of motion. We conclude that a modified embedded-atom potential achieves the best compromise in terms of static and dynamic screw dislocation properties, although at an expense of about ten-fold compared to central potentials.

Authors+Show Affiliations

Instituto de Fusión Nuclear, Universidad Politécnica de Madrid, E-28006 Madrid, Spain.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

23370442

Citation

Cereceda, D, et al. "Assessment of Interatomic Potentials for Atomistic Analysis of Static and Dynamic Properties of Screw Dislocations in W." Journal of Physics. Condensed Matter : an Institute of Physics Journal, vol. 25, no. 8, 2013, p. 085702.
Cereceda D, Stukowski A, Gilbert MR, et al. Assessment of interatomic potentials for atomistic analysis of static and dynamic properties of screw dislocations in W. J Phys Condens Matter. 2013;25(8):085702.
Cereceda, D., Stukowski, A., Gilbert, M. R., Queyreau, S., Ventelon, L., Marinica, M. C., ... Marian, J. (2013). Assessment of interatomic potentials for atomistic analysis of static and dynamic properties of screw dislocations in W. Journal of Physics. Condensed Matter : an Institute of Physics Journal, 25(8), p. 085702. doi:10.1088/0953-8984/25/8/085702.
Cereceda D, et al. Assessment of Interatomic Potentials for Atomistic Analysis of Static and Dynamic Properties of Screw Dislocations in W. J Phys Condens Matter. 2013 Feb 27;25(8):085702. PubMed PMID: 23370442.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Assessment of interatomic potentials for atomistic analysis of static and dynamic properties of screw dislocations in W. AU - Cereceda,D, AU - Stukowski,A, AU - Gilbert,M R, AU - Queyreau,S, AU - Ventelon,Lisa, AU - Marinica,M-C, AU - Perlado,J M, AU - Marian,J, Y1 - 2013/01/31/ PY - 2013/2/2/entrez PY - 2013/2/2/pubmed PY - 2013/7/10/medline SP - 085702 EP - 085702 JF - Journal of physics. Condensed matter : an Institute of Physics journal JO - J Phys Condens Matter VL - 25 IS - 8 N2 - Screw dislocations in bcc metals display non-planar cores at zero temperature which result in high lattice friction and thermally-activated strain rate behavior. In bcc W, electronic structure molecular statics calculations reveal a compact, non-degenerate core with an associated Peierls stress between 1.7 and 2.8 GPa. However, a full picture of the dynamic behavior of dislocations can only be gained by using more efficient atomistic simulations based on semiempirical interatomic potentials. In this paper we assess the suitability of five different potentials in terms of static properties relevant to screw dislocations in pure W. Moreover, we perform molecular dynamics simulations of stress-assisted glide using all five potentials to study the dynamic behavior of screw dislocations under shear stress. Dislocations are seen to display thermally-activated motion in most of the applied stress range, with a gradual transition to a viscous damping regime at high stresses. We find that one potential predicts a core transformation from compact to dissociated at finite temperature that affects the energetics of kink-pair production and impacts the mechanism of motion. We conclude that a modified embedded-atom potential achieves the best compromise in terms of static and dynamic screw dislocation properties, although at an expense of about ten-fold compared to central potentials. SN - 1361-648X UR - https://www.unboundmedicine.com/medline/citation/23370442/Assessment_of_interatomic_potentials_for_atomistic_analysis_of_static_and_dynamic_properties_of_screw_dislocations_in_W_ L2 - https://doi.org/10.1088/0953-8984/25/8/085702 DB - PRIME DP - Unbound Medicine ER -