Hydrogen and carbon effects onAl2O3surface phases and metal deposition

Substantial effects of combinations of $\mathrm{H}$ and $\mathrm{C}$ impurities on wetting of metals on $\ensuremath{\alpha}{\text{\ensuremath{-}}\mathrm{Al}}_{2}{\mathrm{O}}_{3}(0001)$ have been found from first principles. An ab initio surface phase diagram for $\mathrm{H}$ and $\mathrm{C}$ on the alumina surface reveals six distinct surface phases, consistent with the observed stability of $\mathrm{H}$ and $\mathrm{C}$ on ${\mathrm{Al}}_{2}{\mathrm{O}}_{3}$ surfaces. These different surface phases exhibit a variety of adhesion strengths with $\mathrm{Cu}$ and $\mathrm{Co}$, and correspondingly different wetting behaviors. These results are consistent with the variety of wetting characteristics observed experimentally.