Diffusive first-order phase transition: nucleation, growth and coarsening in solids

Area of Science:

• Condensed Matter Physics
• Materials Science
• Physical Chemistry

Background:

• First-order phase transitions, including nucleation and growth, are fundamental processes observed across diverse natural and synthetic systems.
• Classical nucleation theory (CNT) and phase-field (PF) modeling offer distinct, yet complementary, perspectives on these transitions.
• Recent advancements in computational methods and experimental techniques necessitate a unified understanding of these approaches.

Purpose of the Study:

• To synthesize current knowledge on classical nucleation theory and phase-field modeling for first-order phase transitions.
• To elucidate the connections and limitations of these seemingly antagonistic approaches.
• To present a unified framework, grounded in macroscopic fluctuation theory, for understanding nucleation, growth, and coarsening.

Main Methods:

• Review and synthesis of existing literature on nucleation and growth theories.
• Extension of the Cahn-Hilliard formalism to model nucleation and growth.
• Discussion of the concept of pseudo-spinodal lines for interpreting experimental data.
• Integration of concepts within the theory of macroscopic fluctuations.

Main Results:

• Demonstration of the links between atomistic (CNT) and continuum (PF) approaches to phase transitions.
• Application of extended Cahn-Hilliard formalism to nucleation and growth, enabling analysis beyond solubility and spinodal limits.
• Identification of new experimental data to test theoretical models.

Conclusions:

• A unified theoretical framework can reconcile classical nucleation theory and phase-field modeling.
• The extended Cahn-Hilliard approach offers a more predictive and versatile tool for studying phase transitions.
• Further development of this unified approach holds promise for advancing materials science and understanding complex phenomena.