Adsorption of fluorine and chlorine on Mg (0001) surface: A density functional theory investigation

The adsorption of low-coverage of F and Cl adatoms on the Mg (0001) surface was investigated using first-principles calculations based on the density functional theory (DFT). The stability of the (2 × 2) structures formed by halogen atoms adsorbed at different sites was determined. The difference between the adsorption of F and Cl on Mg (0001) surface was also discussed. The calculation results show that hollow sites are the energetically most favorable at the low-coverage. It can be concluded from the Mulliken charges and density of states that electrons transfer from the substrate Mg atoms to the adatoms, which leads to the formation of adsorbate bond and further causes the stronger interaction between Mg atom and adatom. The interaction between Cl and Mg atoms is weaker than the interaction between F and Mg.