Please use this identifier to cite or link to this item: http://bura.brunel.ac.uk/handle/2438/28469
Title: A molecular dynamics study on the boundary between homogeneous and heterogeneous nucleation
Authors: Men, H
Keywords: Molecular dynamics;Atomistic simulations;supercooling;amorphous materials;liquid metals;solidification process;nanoparticle;crystallography;alloys;liquid solid interfaces
Issue Date: 7-Mar-2024
Publisher: American Institute of Physics
Citation: Men, H. (2024) 'A molecular dynamics study on the boundary between homogeneous and heterogeneous nucleation', The Journal of Chemical Physics, 160 (9)., 094702, pp. 1 - 14. doi: 10.1063/5.0192069.
Abstract: The large discrepancy among the nucleation kinetics extracted from experimental measurements and computer simulations and the prediction of the classical nucleation theory (CNT) has stimulated intense arguments about its origin in the past decades, which is crucially relevant to the validity of the CNT. In this paper, we investigate the atomistic mechanism of the nucleation in liquid Al in contact with amorphous substrates with atomic-level smooth/rough surfaces, using molecular dynamics (MD) simulations. This study reveals that the slightly distorted local fcc/hcp structures in amorphous substrates with smooth surfaces can promote heterogeneous nucleation through a structural templating mechanism, and on the other hand, homogeneous nucleation will occur at a larger undercooling through a fluctuation mechanism if the surface is rough. Thus, some impurities, previously thought to be impotent, could be activated in the homogeneous nucleation experiments. We further find that the initial growth of the nucleus on smooth surfaces of amorphous substrates is one order of magnitude faster than that in homogeneous nucleation. Both these factors could significantly contribute to the discrepancy in the nucleation kinetics. This study is also supported by a recent study of the synthesis of high-entropy alloy nanoparticles assisted with the liquid metal Ga [Cao et al., Nature 619, 73 (2023)]. In this study, we established that the boundary existed between homogeneous and heterogeneous nucleation, i.e., the structural templating is a general mechanism for heterogeneous nucleation, and in its absence, homogeneous nucleation will occur through the fluctuation mechanism. This study provides an in-depth understanding of the nucleation theory and experiments.
Description: Data Availability: The data that support the findings of this study are available within the article.
Supplementary material: The supplementary material is available online at: https://pubs.aip.org/jcp/article-supplement/3267965/zip/094702_1_5.0192069.suppl_material .
URI: https://bura.brunel.ac.uk/handle/2438/28469
DOI: https://doi.org/10.1063/5.0192069
ISSN: 0021-9606
Other Identifiers: ORCiD: Hua Men https://orcid.org/0000-0003-3625-6043
094702
Appears in Collections:Brunel Centre for Advanced Solidification Technology (BCAST)

Files in This Item:
File Description SizeFormat 
FullText.pdfCopyright © 2024 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). Creative Commons: This is an open access article distributed under the terms of the Creative Commons CC BY license, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. You are not required to obtain permission to reuse this article.12.8 MBAdobe PDFView/Open


This item is licensed under a Creative Commons License Creative Commons