Nucleation near the eutectic point in a Potts-lattice gas model

Area of Science:

• Materials Science
• Computational Chemistry
• Statistical Physics

Background:

• Nucleation is critical in materials formation, especially at eutectic compositions where multiple phases compete.
• Classical nucleation theory provides a framework but requires accurate free energy calculations.
• Simulating nucleation in closed systems differs from open systems, necessitating advanced methods.

Purpose of the Study:

• To investigate nucleation phenomena at and near the eutectic composition using the Potts-lattice gas model.
• To compute the free energy landscape for competing nucleation products using rare-event methods.
• To develop corrections for converting free energy surfaces between closed and open simulation systems.

Main Methods:

• Utilized the Potts-lattice gas model for simulating nucleation.
• Employed rare-event methods to determine the free energy landscape.
• Applied short trajectory analysis at the barrier top to obtain prefactors.
• Introduced a procedure to tune semigrand Monte Carlo moves for system dynamics.
• Developed corrections for free energy surfaces from canonical to semigrand simulations.

Main Results:

• Non-dimensionalized nucleation rates align with predictions from classical nucleation theory.
• Successfully computed free energy landscapes for competing nucleation products.
• The developed corrections extend applicability to competitive nucleation at eutectic points.
• Tuning Monte Carlo moves improved the resemblance of small closed system dynamics to infinite systems.

Conclusions:

• The Potts-lattice gas model combined with rare-event methods is effective for studying eutectic nucleation.
• New corrections enable accurate free energy surface analysis for competitive nucleation in open systems.
• This work advances the understanding and simulation of complex nucleation processes in materials science.