Using a first principles methodology, we find that $\mathrm{Al}\mathrm{}\left(111\right)/\mathrm{C}\mathrm{}\left(111\right)-1\mathrm{}\times 1$ is energetically favored over $\mathrm{Al}\mathrm{}\left(111\right)/\mathrm{C}\mathrm{}\left(111\right)-2\mathrm{}\times 1$ even though reconstructed diamond is the stable surface structure. Overlapping Al and diamond $p$ states at the unreconstructed interface result in strong adhesion, which leads to an adhesive transfer of two Al layers to the diamond during progressive tensile straining. Decohesion occurs as a jump-to-separate process once the interfacial strength is exceeded. Hydrogen passivation of the diamond leads to negligible adhesion and no transfer of Al.

• Received 10 September 2003

DOI:https://doi.org/10.1103/PhysRevB.68.201403