Self-diffusion and macroscopic diffusion of hydrogen in amorphous metals from first-principles calculations

Area of Science:

• Materials Science
• Physical Chemistry
• Computational Materials Science

Background:

• Interstitial hydrogen diffusion is critical for amorphous metals used in hydrogen purification membranes.
• Understanding hydrogen transport in amorphous alloys is essential for optimizing membrane performance.

Purpose of the Study:

• To characterize interstitial hydrogen diffusion in amorphous metals using first-principles methods.
• To demonstrate the utility of kinetic Monte Carlo simulations for assessing hydrogen diffusion coefficients.

Main Methods:

• Utilized first-principles calculations to derive diffusion rates.
• Employed kinetic Monte Carlo simulations to model interstitial hydrogen diffusion.
• Investigated amorphous Fe(3)B as a model system.

Main Results:

• Transport diffusion coefficient of hydrogen is strongly concentration-dependent in amorphous metals.
• The transport diffusion coefficient differs from the self-diffusion coefficient at non-dilute concentrations.
• First-principles guided simulations accurately predict both self- and transport diffusion coefficients.

Conclusions:

• First-principles based methods are effective for characterizing hydrogen diffusion in amorphous metals.
• Kinetic Monte Carlo simulations are valuable tools for screening amorphous alloys for hydrogen purification membranes.
• Accurate determination of transport diffusion coefficients is crucial for practical applications.