2009 Volume 15 Issue 3 Pages 303-306
In order to study correlation between oxide layers on hydrogen storage metals such as V(111), polycrystalline Vanadium, and VCrTa alloy and hydrogen desorption temperature, the surfaces covered by native oxides have been analyzed by photoemission spectroscopy using soft x-ray synchrotron radiation. Depth analyses of the oxide layers were performed by changing synchrotron radiation energy to estimate the oxide thickness. The native oxide layer was disappeared by thermal annealing up to 713 K for the V(111) surface. The oxide layers of the poly V and the VCrTa alloy, however, were remained even at 873 K. Although the oxides of V and Cr were disappeared, Ta oxides were remained. The re-arrangement of oxidation took place in the oxide layer of the VCrTa alloy by thermal annealing. The oxidation of Ta controlled oxide thickness in the VCrTa alloy. The formation of an artificial oxide layer could be controlled using supersonic oxygen molecular beams.
