Reconciling atomistic and macroscopic models of nucleation
Schematic representation of a solid nucleating within the molten phase © COSMO / 2017 EPFL
Nucleation is a key step in bulk phase transitions, but experimental studies are notoriously difficult. Atomistic simulations make it possible to investigate this phenomenon at the nanoscale, but it is not straightforward to map molecular-level insight to the macroscopic models that give an intuitive understanding of nucleation.
Macroscopic theories of nucleation such as classical nucleation theory envision that clusters of the bulk stable phase forminside the bulk metastable phase. Molecular dynamics simulations are often used to elucidate nucleation mechanisms, by capturing the microscopic configurations of all the atoms. In a paper recently published on the Journal of Chemical physics, researchers from the Laboratory of computational Science and Modelling introduce a thermodynamic model that links macroscopic theories and atomic-scale simulationsand thus provide a simple and elegant framework for testing the limits of classical nucleation theory.