Abstract:
The oxidation of molybdenum as an evaporated film and of its annealed surface was investigated
by Energy Loss Spectroscopy (ELS) combined with Auger Electron Spectroscopy (AES). The
10 eV and the lower energy loss peaks towards 5 eV were identified as the clean surface and the
oxidized layer surface plasma loss peaks, respectively. The behaviours of these surface plasma loss
spectra revealed that the oxidation of the evaporated film surface proceeded uniformly, rapidly and
without any induction period under vacuum of 10"7 Torr, whereas that of the annealed sample
proceeded more slowly through “ oxidized patches ”, exhibiting a considerable induction period
under the same vacuum conditions. These phenomena were interpreted with reference to the surface
conditions and structures studied by the AES and ELS; the fresh evaporated surface is clean and
rough, whereas the annealed surface is smoothed by the heat-treatment and contaminated by sulphur
and carbon which partially cover the active surfaces and give rise to the patchy surface oxidation.
