Au–K co-deposition on MgO(2L)/Ag(0 0 1): A first principles study

The Au and K co-deposition on MgO(2L)/Ag(0 0 1) is studied by first principles calculations. By comparing the formation energies, several stable Au–K surface structures with different Au–K ratios are found. The Coulomb attractions between Au and K atoms play an essential role in the stabilities of these structures. The addition of K atoms in the Au/MgO(2L)/Ag(0 0 1) system modifies the electronic properties of Au significantly. The charge transfer from K atoms to Au atoms is the dominant one, which leads to the significant increase of Au charges, while the charge transfer from the substrate to Au atoms is suppressed. In the stable structures, the charges of Au atoms are different, which may show different Au reactivities.