Anomalous diffusion along metal/ceramic interfaces

Area of Science:

• Materials Science
• Surface Science
• Solid State Physics

Background:

• Interface diffusion is critical for metal/ceramic devices.
• Fast diffusion can degrade performance and stability.

Purpose of the Study:

• Investigate the mechanism and rate of Ni diffusion at the Ni/α-Al2O3 interface.
• Develop a predictive model for interface diffusion in metal/ceramic systems.

Main Methods:

• Continuum diffusion analysis.
• Ab initio calculations (density functional theory).
• Experimental observation of hole formation.

Main Results:

• Nickel diffusion along the Ni/α-Al2O3 interface is unexpectedly rapid.
• Lower vacancy formation and migration energies at the coherent interface compared to bulk Ni.
• Interface diffusion activation energy is similar to high-angle grain boundaries.

Conclusions:

• Fast metal diffusion along metal/ceramic interfaces is a common phenomenon.
• The developed model accurately predicts interface diffusion rates.
• Interface diffusion is not universally fast across all metal/ceramic systems.