First-principles study of initial stage of Ni thin-film growth on a TiO2 (110) surface

The bonding structure and binding character for the initial stage of thin-f ilm growth of Ni on a rutile (110) surface were studied using first-princip les density functional theory. Our results show that, in the first monolaye r, Ni atoms are preferentially adsorbed on top of bridging oxygen atoms and upon secondary surface oxygen. The bond strength between Ni adatom and sub strate is much stronger than that between Ni adatoms. About 0.3 electrons a re transferred from Ni atoms to substrate in low coverage; the adsorption o f additional Ni atoms on neighboring sites decreases this transfer. In addi tion to the ionic bonding component, some covalent character is found in th e Ni adatom-substrate bond.