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Long-wavelength density fluctuations as nucleation precursors
1Center for Nonlinear Phenomena and Complex Systems, Code Postal 231, Université Libre de Bruxelles, Blvd. du Triomphe, 1050 Brussels, Belgium.
Physical Review. E
|June 25, 2020
Summary
Nonclassical nucleation theory predicts that initial clusters form from widespread, low-density fluctuations. Kinetic Monte Carlo simulations confirm this, showing nucleation begins with extended, low-amplitude density fluctuations, not small clusters.
Area of Science:
- Physical Chemistry
- Materials Science
- Thermodynamics
Background:
- Classical nucleation theory describes phase transitions with small, dense clusters.
- Nonclassical nucleation theory posits initial nucleation involves large-scale, low-density fluctuations.
- Understanding early-stage nucleation is crucial for controlling material formation.
Purpose of the Study:
- To investigate the initial stages of diffusion-limited nucleation.
- To test predictions of nonclassical nucleation theory regarding cluster formation.
- To compare simulation results with theoretical models of nucleation.
Main Methods:
- Utilized kinetic Monte Carlo simulations.
- Employed forward flux sampling techniques for enhanced sampling.
- Analyzed density fluctuations during the nucleation process.
Main Results:
- Simulations confirmed nucleation begins with low-amplitude, spatially extended density fluctuations.
- Observed initial clusters with low density and large spatial extent.
- Results contradict the classical nucleation picture of small, dense clusters.
Conclusions:
- The study validates key predictions of nonclassical nucleation theory.
- Nonclassical nucleation mechanisms are significant in diffusion-limited phase transitions.
- Findings advance the understanding of nucleation phenomena in vapors and solutions.
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