Adsorption of transition metal atoms on defective MgO(001) Surfaces: Atomic and electronic structures

The adsorption of transition metal (TM) atoms (Cu, Ag, Au, Ni, Pd and Pt) on O-defective MgO(001) surfaces has been studied using ab initio electronic structure calculations based on the density functional theory. The F_s center (surface oxygen vacancy), the most common defect on the surface, was considered here. The calculations in this study showed that the metal adatoms bind more strongly on the F_s center than on the regular surface sites, in agreement with previous works. Also, systematically examined was the interaction between the states corresponding to the TM electrons and the surface defect states. Stronger orbital mixing of the TM states with the defect states was found. This indicates that the F_s center plays an important role in the alignment of the energy levels of the TM adatoms on the O-defective MgO(001) surface.