We have used electron energy-loss spectroscopy to search for differences in the energy-loss near-edge structure of SnO, ${\text{SnO}}_2$, and an intermediate oxide, with a view to distinguishing them unambigously. We have found that the oxygen $K$ edge exhibits clear differences that can be used for fingerprinting each phase. The oxygen edge appears at the same position for each phase whereas a chemical shift of the Sn $M_{4,5}$ edge of about $3.5\text{eV}$ was observed between phases with Sn in $2+$ and $4+$ oxidation states. Both observations can be used to distinguish between the three phases, allowing their on-line identification within nanostructured materials.

• Received 19 December 2003

DOI:https://doi.org/10.1103/PhysRevB.69.233304