An investigation of the ESD O/O+ ratio from V2O5 and oxidized V

The ratio of oxygen atoms to ions (O/O+) generated during electron stimulated desorption (ESD) from V2O5 and oxidized V foil has been investigated. Desorbates were probed directly with high resolution quadrupole mass spectrometry. X-ray photoelectron spectroscopy was used as an indirect probe to measure the ESD induced surface oxygen loss. Despite the number of ESD target preparation methods and experimental variations used, ESD O atoms were never detected. Accordingly, the results are presented as an upper limit to the ESD O/O+ ratio, as determined by the neutral detection limit of the given instrumental method. The results of the mass spectral probe were an O/O+ ratio of ⋍54 (oxidized V foil), 58 (18O2V2O5) and 160 (V2O5). From the XPS results (oxidized V foil) the ratio was determined to be ⋍4.