First-principles study for quasi-static growth model in FeAl intermetallic based on Wulff cluster model

Area of Science:

• Materials Science
• Physical Chemistry
• Crystallography

Background:

• Understanding the structure of mesoscopic crystals in liquid alloys is crucial for materials development.
• The Wulff shape model describes equilibrium crystal structures based on surface energies.

Purpose of the Study:

• To investigate the equilibrium structures of FeAl mesoscopic crystals in liquid state alloys.
• To develop a quasi-static growth model for predicting crystal shape evolution.
• To analyze the influence of chemical environment on crystal morphology.

Main Methods:

• Utilized the Wulff cluster model to determine equilibrium crystal structures.
• Incorporated chemical potential for non-stoichiometric surface terminations.
• Developed a quasi-static growth model based on sequential (sub-)monolayer addition.
• Simulated surface adsorption and concentration trends for FeAl.

Main Results:

• Equilibrium crystal shapes (Wulff shapes) were determined for FeAl.
• Cluster shapes were shown to vary with the chemical environment (chemical potential).
• A sequential growth model demonstrated evolving Wulff shapes during the growth process.
• Preliminary validation through surface concentration and adsorption simulations.

Conclusions:

• The proposed quasi-static growth model provides insights into FeAl crystal formation.
• The model can theoretically analyze growth processes and nucleation barriers.
• Understanding shape evolution is key for controlling mesocrystal formation in alloys.