On the reaction coordinate for seeded crystallisation

Abstract

Small pre-structured seeds introduced into an undercooled fluid are known to increase the crystal nucleation rate by some orders of magnitude, if the structure of the seeds is commensurate with the bulk crystalline phase. The presence of such seeds also alters the crystallisation mechanism by favouring particular structures at the early stages of the nucleation process. Here, we study with computer simulations the effect of small face-centred cubic and body-centred cubic seeds on the crystallisation of a Lennard-Jones liquid in the strongly undercooled regime. We find that seeds with body-centred cubic structure lead to a larger enhancement of the crystallisation rate than face-centred cubic seeds. An analysis of recurrence times reveals that the size of the largest crystalline cluster used as reaction coordinate is affected by pronounced memory effects, which depend on the particular seed structure and point to the importance of structural information in the definition of a good reaction coordinate for crystallisation.

Keywords:

• heterogeneous crystallisation
• reaction coordinate
• computer simulations
• Lennard-Jones system

Acknowledgements

The computational results presented have been achieved using the Vienna Scientific Cluster (VSC). We acknowledge financial support of the Austrian Science Fund (FWF) within the project V 305-N27 as well as SFB ViCoM (grant F41).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

We acknowledge financial support of the Austrian Science Fund (FWF) within the project V 305-N27 as well as SFB ViCoM [grant F41].