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Phase-field crystal modeling of heteroepitaxy and exotic modes of crystal nucleation

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journal contribution
posted on 2017-11-03, 09:42 authored by Frigyes Podmaniczky, Gyula TothGyula Toth, Gyorgy Tegze, Tamas Pusztai, Laszlo Granasy
We review recent advances made in modeling heteroepitaxy, two-step nucleation, and nucleation at the growth front within the framework of a simple dynamical density functional theory, the Phase-Field Crystal (PFC) model. The crystalline substrate is rep-resented by spatially confined periodic potentials. We investigate the misfit dependence of the critical thickness in the Stranski–Krastanov growth mode in isothermal studies. Apparently, the simulation results for stress release via the misfit dislocations fit better to the People–Bean model than to the one by Matthews and Blakeslee. Next, we investigate structural aspects of two-step crystal nucleation at high undercoolings, where an amorphous precursor forms in the first stage. Finally, we present results for the formation of new grains at the solid-liquid interface at high supersaturations / supercoolings, a phenomenon termed Growth Front Nucleation (GFN). Results obtained with diffusive dynamics (applicable to colloids) and with a hydrodynamic extension of the PFC theory (HPFC, developed for simple liquids) will be compared. The HPFC simulations indicate two possible mechanisms for GFN.

Funding

This work has been supported by National Agency for Re-search, Development, and Innovation (NKFIH), Hungary un-der contract No. OTKA-K-115959, by the EU FP7 Collabora-tive Project “EXOMET” (contract no. NMP-LA-2012-280421, co-funded by ESA), and by the ESA MAP/PECS projects “MAGNEPHAS III” (ESTEC Contract No. 40000110756/11/ NL/KML) and “GRADECET” (ESTEC Contract No. 40000 110759/11/ NL/KML).

History

School

  • Science

Department

  • Mathematical Sciences

Published in

Journal of Crystal Growth

Volume

457

Pages

24 - 31

Citation

PODMANICZKY, F. ...et al., 2017. Phase-field crystal modeling of heteroepitaxy and exotic modes of crystal nucleation. Journal of Crystal Growth, 457, pp. 24-31.

Publisher

© Elsevier

Version

  • AM (Accepted Manuscript)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/

Publication date

2017

Notes

This paper was accepted for publication in the journal Journal of Crystal Growth and the definitive published version is available at https://doi.org/10.1016/j.jcrysgro.2016.06.056

ISSN

0022-0248

Language

  • en