Atomistic simulations of amorphous alumina surfaces

The surface structure of amorphous Al2O3 has been studied using atomistic molecular dynamics simulations. The density profiles indicate that oxygen is preferred at the surface causing Al enrichment just below (< 2 A) the surface. Distributions of coordination numbers, bondlengths and bond angles indicate that edge sharing Al tetrahedra configurations are more preferred at the surface than in the bulk. Structural differences of amorphous and crystalline alumina surfaces are discussed.