Atomic Diffusion in α-iron across the Curie Point: An Efficient and Transferable Ab Initio-Based Modeling Approach

Area of Science:

• Computational Materials Science
• Physical Chemistry
• Condensed Matter Physics

Background:

• Atomic diffusion in iron (Fe) alloys is difficult to predict accurately.
• Thermal magnetic excitations and magnetic transitions complicate diffusion modeling.

Purpose of the Study:

• To develop an efficient computational approach for predicting atomic diffusion in Fe alloys.
• To investigate the influence of magnetic properties on diffusion coefficients.

Main Methods:

• Utilizing Monte Carlo simulations.
• Employing ab initio-based effective interaction models.
• Incorporating a quantum treatment of spins for magnetic phenomena.

Main Results:

• Successfully predicted the temperature evolution of self- and copper (Cu) diffusion coefficients in alpha-iron (α-iron).
• Observed and explained diffusion acceleration around the Curie point.
• Demonstrated the dominance of magnetic disorder over chemical effects in dilute Fe systems.

Conclusions:

• The proposed Monte Carlo simulation approach effectively captures magnetic effects on atomic diffusion.
• Magnetic disorder plays a crucial role in diffusion behavior, especially near magnetic transitions.
• Accurate diffusion prediction in Fe alloys requires considering quantum spin treatments.