EELS Investigations of Different Niobium Oxide Phases

Electron energy loss spectra in conjunction with near-edge fine structures of purely stoichiometric niobium monoxide (NbO) and niobium pentoxide (Nb 2 O 5 ) reference materials were recorded. The structures of the niobium oxide reference materials were checked by selected area electron diffraction to ensure a proper assignment of the fine structures. NbO and Nb 2 O 5 show clearly different energy loss near-edge fine structures of the Nb-M 4,5 and -M 2,3 edges and of the O-K edge, reflecting the specific local environments of the ionized atoms. To distinguish the two oxides in a quantitative manner, the intensities under the Nb-M 4,5 as well as Nb-M 2,3 edges and the O-K edge were measured and their ratios calculated. k -factors were also derived from these measurements.