Heterogeneous Nucleation Mechanisms in Systems with Large Lattice Misfit Demonstrated by the Pb(<i>l</i>)/Cu(<i>s</i>) System
Our current understanding of heterogeneous nucleation has been largely confined to the classical nucleation theory (CNT) that was postulated over 100 years ago based on a thermodynamic approach. Further advances in heterogeneous nucleation research requires detailed knowledge of atomistic activities...
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2022-09-01
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author | Hua Men Zhongyun Fan |
author_facet | Hua Men Zhongyun Fan |
author_sort | Hua Men |
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description | Our current understanding of heterogeneous nucleation has been largely confined to the classical nucleation theory (CNT) that was postulated over 100 years ago based on a thermodynamic approach. Further advances in heterogeneous nucleation research requires detailed knowledge of atomistic activities at the liquid/substrate interface. In this work, using a classical molecular dynamics (MD) simulation, we investigated the atomistic mechanisms of heterogeneous nucleation in systems with a large lattice misfit (|<i>f</i>| > 12.5%) demonstrated by the liquid Pb and solid Cu system (denoted as the Pb(<i>l</i>)/Cu(<i>s</i>) system) with a misfit of 27.3%. We found that heterogeneous nucleation in systems with a large misfit takes place in two distinctive steps: (1) Prenucleation creates a coincidence site lattice (CSL) on the substrate surface to accommodate the majority (<i>f</i><sub>csl</sub>) of the initial misfit (<i>f</i>) and (2) Heterogeneous nucleation accommodates the residual misfit <i>f</i><sub>r</sub> (<i>f</i><sub>r</sub> = misfit − <i>f</i><sub>csl</sub>) at the nucleation temperature to create a plane of the new solid phase (a two-dimensional (2D) nucleus) through either a three-layer dislocation mechanism if <i>f</i><sub>r</sub> < 0 or a three-layer vacancy mechanism if <i>f</i><sub>r</sub> > 0, such as in the case of the Pb(<i>l</i>)/Cu(<i>s</i>) system. |
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spelling | doaj.art-08fadbcc52b94301909a49e06560abdb2023-11-24T01:17:20ZengMDPI AGMetals2075-47012022-09-011210158310.3390/met12101583Heterogeneous Nucleation Mechanisms in Systems with Large Lattice Misfit Demonstrated by the Pb(<i>l</i>)/Cu(<i>s</i>) SystemHua Men0Zhongyun Fan1Brunel Centre for Advanced Solidification Technology (BCAST), Brunel University London, Uxbridge, Middlesex UB8 3PH, UKBrunel Centre for Advanced Solidification Technology (BCAST), Brunel University London, Uxbridge, Middlesex UB8 3PH, UKOur current understanding of heterogeneous nucleation has been largely confined to the classical nucleation theory (CNT) that was postulated over 100 years ago based on a thermodynamic approach. Further advances in heterogeneous nucleation research requires detailed knowledge of atomistic activities at the liquid/substrate interface. In this work, using a classical molecular dynamics (MD) simulation, we investigated the atomistic mechanisms of heterogeneous nucleation in systems with a large lattice misfit (|<i>f</i>| > 12.5%) demonstrated by the liquid Pb and solid Cu system (denoted as the Pb(<i>l</i>)/Cu(<i>s</i>) system) with a misfit of 27.3%. We found that heterogeneous nucleation in systems with a large misfit takes place in two distinctive steps: (1) Prenucleation creates a coincidence site lattice (CSL) on the substrate surface to accommodate the majority (<i>f</i><sub>csl</sub>) of the initial misfit (<i>f</i>) and (2) Heterogeneous nucleation accommodates the residual misfit <i>f</i><sub>r</sub> (<i>f</i><sub>r</sub> = misfit − <i>f</i><sub>csl</sub>) at the nucleation temperature to create a plane of the new solid phase (a two-dimensional (2D) nucleus) through either a three-layer dislocation mechanism if <i>f</i><sub>r</sub> < 0 or a three-layer vacancy mechanism if <i>f</i><sub>r</sub> > 0, such as in the case of the Pb(<i>l</i>)/Cu(<i>s</i>) system.https://www.mdpi.com/2075-4701/12/10/1583nucleationatomistic simulationsolid/liquid interfacecoincidence site lattice (CSL)lattice misfit |
spellingShingle | Hua Men Zhongyun Fan Heterogeneous Nucleation Mechanisms in Systems with Large Lattice Misfit Demonstrated by the Pb(<i>l</i>)/Cu(<i>s</i>) System Metals nucleation atomistic simulation solid/liquid interface coincidence site lattice (CSL) lattice misfit |
title | Heterogeneous Nucleation Mechanisms in Systems with Large Lattice Misfit Demonstrated by the Pb(<i>l</i>)/Cu(<i>s</i>) System |
title_full | Heterogeneous Nucleation Mechanisms in Systems with Large Lattice Misfit Demonstrated by the Pb(<i>l</i>)/Cu(<i>s</i>) System |
title_fullStr | Heterogeneous Nucleation Mechanisms in Systems with Large Lattice Misfit Demonstrated by the Pb(<i>l</i>)/Cu(<i>s</i>) System |
title_full_unstemmed | Heterogeneous Nucleation Mechanisms in Systems with Large Lattice Misfit Demonstrated by the Pb(<i>l</i>)/Cu(<i>s</i>) System |
title_short | Heterogeneous Nucleation Mechanisms in Systems with Large Lattice Misfit Demonstrated by the Pb(<i>l</i>)/Cu(<i>s</i>) System |
title_sort | heterogeneous nucleation mechanisms in systems with large lattice misfit demonstrated by the pb i l i cu i s i system |
topic | nucleation atomistic simulation solid/liquid interface coincidence site lattice (CSL) lattice misfit |
url | https://www.mdpi.com/2075-4701/12/10/1583 |
work_keys_str_mv | AT huamen heterogeneousnucleationmechanismsinsystemswithlargelatticemisfitdemonstratedbythepbilicuisisystem AT zhongyunfan heterogeneousnucleationmechanismsinsystemswithlargelatticemisfitdemonstratedbythepbilicuisisystem |