Photoemission study on oxide at poly-vanadium surface

Teraoka, Yuden; Yoshigoe, Akitaka ; Harries, J.

Correlation between thermal desorption of hydrogen and chemical bonding states in the over-layer has been investigated via photoemission spectroscopy with synchrotron radiation for poly-crystalline Vanadium surface. An O1s photoemission spectrum for the native over-layer consisted of at least two components. The lower binding energy component was bulk sensitive and the other was surface sensitive. V2p photoemission peaks contributed from bulk could be observed with photon energy larger than 795 eV so that the thickness of native over-layer might be at least 3 nm. By flash heating at 873 K, the O1s and the Vanadium oxide peaks disappeared. The clean surface was irradiated by the oxygen beams with translational energy of 0.48 eV and 2.3 eV. In both cases, similar oxide was formed. But, the thickness was smaller than that of native oxide. The artificial oxide could be removed by the same heating procedure as the native oxide.