Anomalous entropy-driven kinetics of dislocation nucleation
Abstract The kinetics of dislocation reactions, such as dislocation multiplication, controls the plastic deformation in crystals beyond their elastic limit, therefore critical mechanisms in a number of applications in materials science. We present a series of large-scale molecular dynamics simulatio...
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Nature Portfolio
2025-01-01
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| Series: | Nature Communications |
| Online Access: | https://doi.org/10.1038/s41467-025-56272-4 |
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| author | Soumendu Bagchi Danny Perez |
| author_facet | Soumendu Bagchi Danny Perez |
| author_sort | Soumendu Bagchi |
| collection | DOAJ |
| description | Abstract The kinetics of dislocation reactions, such as dislocation multiplication, controls the plastic deformation in crystals beyond their elastic limit, therefore critical mechanisms in a number of applications in materials science. We present a series of large-scale molecular dynamics simulations that shows that one such type of reactions, the nucleation of dislocation at free surfaces, exhibit unconventional kinetics, including unexpectedly large nucleation rates under compression, very strong entropic stabilization under tension, as well as strong non-Arrhenius behavior. These unusual kinetics are quantitatively rationalized using a variational transition state theory approach coupled with an efficient numerical scheme for the estimation of vibrational entropy changes. These results highlight the need for a variational treatment of the kinetics to quantitatively capture dislocation reaction kinetics, especially at low-to-moderate strains where large deformations are required to activate reactions. These observations suggest possible explanations to previously observed unconventional deformation kinetics in both molecular dynamics simulations and experiments. |
| format | Article |
| id | doaj-art-369432fee7b54903ae22bece127f681d |
| institution | Kabale University |
| issn | 2041-1723 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Nature Communications |
| spelling | doaj-art-369432fee7b54903ae22bece127f681d2025-01-26T12:41:01ZengNature PortfolioNature Communications2041-17232025-01-011611910.1038/s41467-025-56272-4Anomalous entropy-driven kinetics of dislocation nucleationSoumendu Bagchi0Danny Perez1Theoretical Division, Los Alamos National LaboratoryTheoretical Division, Los Alamos National LaboratoryAbstract The kinetics of dislocation reactions, such as dislocation multiplication, controls the plastic deformation in crystals beyond their elastic limit, therefore critical mechanisms in a number of applications in materials science. We present a series of large-scale molecular dynamics simulations that shows that one such type of reactions, the nucleation of dislocation at free surfaces, exhibit unconventional kinetics, including unexpectedly large nucleation rates under compression, very strong entropic stabilization under tension, as well as strong non-Arrhenius behavior. These unusual kinetics are quantitatively rationalized using a variational transition state theory approach coupled with an efficient numerical scheme for the estimation of vibrational entropy changes. These results highlight the need for a variational treatment of the kinetics to quantitatively capture dislocation reaction kinetics, especially at low-to-moderate strains where large deformations are required to activate reactions. These observations suggest possible explanations to previously observed unconventional deformation kinetics in both molecular dynamics simulations and experiments.https://doi.org/10.1038/s41467-025-56272-4 |
| spellingShingle | Soumendu Bagchi Danny Perez Anomalous entropy-driven kinetics of dislocation nucleation Nature Communications |
| title | Anomalous entropy-driven kinetics of dislocation nucleation |
| title_full | Anomalous entropy-driven kinetics of dislocation nucleation |
| title_fullStr | Anomalous entropy-driven kinetics of dislocation nucleation |
| title_full_unstemmed | Anomalous entropy-driven kinetics of dislocation nucleation |
| title_short | Anomalous entropy-driven kinetics of dislocation nucleation |
| title_sort | anomalous entropy driven kinetics of dislocation nucleation |
| url | https://doi.org/10.1038/s41467-025-56272-4 |
| work_keys_str_mv | AT soumendubagchi anomalousentropydrivenkineticsofdislocationnucleation AT dannyperez anomalousentropydrivenkineticsofdislocationnucleation |