The movement of ion pairs on the surfaces of simple oxides was examined. By using temperature-accelerated dynamics, the elementary processes which were involved were identified, and their activation energies were used as input to kinetic Monte Carlo simulations. Results were presented for the motion of BaO and SrO ion pairs on the (100) surfaces of BaO and SrO, respectively, and the formation of island pairs on these surfaces was studied. The simulations revealed the importance of exchange mechanisms in surface diffusion and the growth of oxides. Exchange mechanisms could dominate transport processes, on terraces and steps, for both homo-epitaxial and hetero-epitaxial growth. It was suggested that an unavoidable mixing, which occurred when an exchange mechanism operated, had to be considered when attempting to grow sharp interfaces in oxide nanostructures.

Simulating Surface Diffusion and Surface Growth in Ceramics. M.Y.Lavrentiev, D.J.Harris, J.H.Harding, N.L.Allan, J.A.Purton: Dalton Transactions, 2004, 19, 3071-5