Electronic structure of silver oxides investigated by AgL XANES spectroscopy

The chemistry of binary and multinary silver oxides spans from subvalent sp ecies (with a mean oxidation number for Pig smaller than +1) to compounds w ith Ag in high oxidation states as +2 and +3. We have investigated a range of silver oxides, including the binary compounds Ag2O, AgO, Ag3O4 and Ag2O3 as well as subvalent ternary oxides, by AgL3 and AgL1 XANES spectroscopy. The different valence states of silver are clearly reflected in AgL3 and Ag L1 XANES spectra. The method thus allows the determination of average oxida tion numbers. In addition, the degree of electronic interaction (localized or delocalized electronic states) in silver-oxygen compounds can be estimat ed on the basis of AgL3 XANES spectra.