Stoichiometry and valence measurements of niobium oxides using electron energy‐loss spectroscopy

Summary Qualitative and quantitative electron energy‐loss spectroscopy analyses have been performed on niobium and stable niobium oxides (NbO, NbO 2 and Nb 2 O 5 ). At integration windows (Δ) greater than 75 eV, k‐factor analysis can be used to distinguish between the stoichiometry of the three oxides within 5.7% error. As seen in other metal oxides, with increasing oxidation state the metal ionization edges shift to higher energies relative to the O‐K edge. Normalized M 2,3 white‐line intensities show a strong correlation with 4 d occupancy for each compound. The data are in correspondence with that observed in the literature for 4 d transition metals using normalized L 2,3 white lines. Lastly, a distinctive energy‐loss near‐edge, structure of the O‐K edge was observed for each oxide, which could be used as a fingerprint for analysis of unknowns.