Systematic improvement of classical nucleation theory.

Area of Science:

• Physical Chemistry
• Materials Science
• Thermodynamics

Background:

• Classical nucleation theory (CNT) is widely used to model solid cluster formation in liquids.
• Estimating interface free energies from nucleation barriers is crucial for understanding phase transitions.
• Existing models often assume sharp, spherical interfaces, which may not reflect reality.

Purpose of the Study:

• To re-evaluate the applicability of CNT for calculating solid cluster formation free energy.
• To assess the accuracy of CNT-derived interface free energies.
• To investigate refinements to nucleation barrier theory.

Main Methods:

• Utilized hard sphere and NaCl freezing transitions as test cases.
• Applied corrections for non-sharp solid-liquid interfaces.
• Incorporated adjustments for nonspherical cluster shapes.
• Performed extensive calculations using the Ising model.

Main Results:

• CNT-based interface free energy estimates were found to be generally inaccurate.
• Corrections for non-sharp, fluctuating interfaces significantly improved barrier shape accuracy.
• Refined nucleation barrier theories better explain experimental solid nucleation rates in colloids.

Conclusions:

• Classical nucleation theory requires significant refinement for accurate solid cluster formation analysis.
• Non-sharp interface and cluster shape corrections are critical for interpreting nucleation data.
• Accurate interface tension extraction relies on these advanced nucleation theories.