Growth and electronic structure of Ag on polar MgO(111) films

The growth and electronic structure of Ag on polar MgO(111) thin films with {100} facets were in situ investigated by low energy electron diffraction and photoemission spectroscopies. The Ag epitaxially grows on faceted MgO(111) surface as Ag(111) films due to the large surface energy of the MgO(111) face in spite of the existence of {100} facets, compared with a three-dimensional growth of Ag on MgO(100) films. Based on the photoemission spectroscopies studies, the shifts of the Ag 3d core level line at the initial coverage are mainly associated with size effects rather than chemical interaction. The results are helpful to the understanding of the growth mechanisms and electronic structure of metals on polar oxide surfaces.