Theoretical insight into Cobalt subnano-clusters adsorption on α-Al2O3 (0001)

Diffusion process of Co adatom on the α-Al2O3 (0001) surface, Al(3) site→O(5) site→Al(4) site. Potential energy surface for diffusion of a single Co atom from Al(3) to O(5) site, and from O(5) to Al(4) site on the surface. The activation energy of the two migration processes from Al(3) to O(5) and O(5) to Al(4) are 0.06 and 0.09 eV, respectively. This implies the monomer is quite mobile on the surface under typical growth conditions.126