Photoemission analyses on oxides at single crystal vanadium surfaces

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

In order to study correlation between hydrogen desorption and chemical bonding states of native over-layer, synchrotron radiation photoemission spectroscopy has been applied for analyses of the oxide, its thermal instability and the artificial oxides formation on V(001) and V(111). O1s photoemission spectra for the over-layer consisted of at least two components. The lower binding energy component was bulk sensitive. V2p photoemission peaks contributed from bulk could be observed with photon energy larger than 795eV for V(111) and 688eV for V(001) so that the over-layer thickness might be at least 2nm and 1.5nm, respectively. The O1s peak decreased to be negligible by heating up to 900K. The clean surface was irradiated by supersonic oxygen molecular beams with translational energy of 2.3eV at room temperature. Although a similar oxide layer was formed, the thickness was smaller than that of native oxide.