Electronic States of the Ag(110)–O(n× 1) Phases Studied by Photoemission and Metastable Deexcitation Spectroscopies

The Ag(110)–O( n × 1) phases have been investigated by angularly resolved photoemission (ARUPS) and deexciation of metastable He atoms (MDS), the phase order being controlled by ground state He diffraction. ARUPS data show a coverage independent, O 2 p x state strongly dispersed along Ȳ. An O 2 p y state appears instead weakly dispersed along showing that the oxygen induced antibonding states are localized on the oxygen rows. MDS data show the depletion of sp metal states near to the Fermi edge with a parallel growth of oxygen induced states as the coverage increases. Indication of the presence of O–Ag bonding levels in the range 6–8 eV binding energy, within the metal d -band region, have been obtained by deconvolution of the MDS spectra. The complementary behaviour with coverage of the sp density of states and of the work function variation suggests a charge transfer from these metal states to the adsorbate atom.