Phase-field modeling of two-dimensional crystal growth with anisotropic diffusion

Area of Science:

• Materials Science
• Physics
• Computational Modeling

Background:

• Thin-film growth is crucial for various technologies.
• Understanding crystallite shape evolution is key to controlling material properties.
• Anisotropic surface kinetics and diffusion significantly influence film morphology.

Purpose of the Study:

• To develop a phase-field model for thin-film growth incorporating anisotropic factors.
• To investigate the impact of anisotropic diffusion on the kinetic Wulff shape.
• To enhance model accuracy with second-order corrections for small supersaturations.

Main Methods:

• Development of a phase-field model for thin-film growth.
• Inclusion of anisotropic step energy, attachment kinetics, and diffusion.
• Incorporation of second-order (thin-interface) corrections.
• Analysis of the kinetic Wulff shape under dominant kinetic anisotropy.

Main Results:

• Anisotropic diffusion plays a significant and counterintuitive role in shaping crystallites.
• Second-order corrections improve model accuracy, especially at low supersaturations.
• The deposition rate and crystal symmetries influence the evolving crystal shape.

Conclusions:

• The developed phase-field model accurately captures anisotropic effects in thin-film growth.
• Anisotropic diffusion is a critical factor modifying the equilibrium Wulff shape.
• The model provides insights into controlling thin-film morphology for technological applications.