Anomalous Diffusion along Metal/Ceramic Interfaces

Abstract

Hole formation in a polycrystalline Ni film on an $\alpha$-Al${}_2$O${}_3$ substrate coupled with a continuum diffusion analysis demonstrates that Ni diffusion along the Ni/$\alpha$-Al${}_2$O${}_3$ interface is surprisingly fast. Ab initio calculations demonstrate that both Ni vacancy formation and migration energies at the coherent Ni/$\alpha$-Al${}_2$O${}_3$ interface are much smaller than in bulk Ni, suggesting that the activation energy for diffusion along coherent Ni/$\alpha$-Al${}_2$O${}_3$ interfaces is comparable to that along (incoherent/high angle) grain boundaries. Based on these results, we develop a simple model for diffusion along metal/ceramic interfaces, apply to a wide range of metal/ceramic systems and validate it with several ab initio calculations. These results suggest that fast metal diffusion along metal/ceramic interfaces should be common, but is not universal.

References in corpus (1)

• Structure and growth of titanium buffer layers on Al2O3(0001)

Cited by in corpus (4)

• Atomistic modeling of metal-nonmetal interphase boundary diffusion
• Atomistic modeling of diffusion processes at Al(Si)/Si(111) interphase boundaries obtained by vapor deposition
• Tailoring epitaxial growth and magnetism in La1-xSrxMnO3 / SrTiO3 heterostructures via temperature-driven defect engineering
• A collapsed interface approach to resolve grain boundaries in finite element simulations of polycrystalline diffusion