Resonant OKα emission spectra of CuGeO3 single-crystal

The electronic structure of CuGeO3 has been studied using soft X-ray absorption and emission spectroscopy. The unoccupied and occupied valence states are reflected by O 1s absorption and OKα emission spectra, respectively. An absorption pre-peak appearing at 531 eV in O 1s absorption spectrum indicates the localized nature of the unoccupied O 2p admixture to Cu 3d states. A large band gap is observed in the absorption–emission spectrum. Some changes of spectral profile of the OKα emission spectra are attributed to the existence of the inequivalent oxygen sites.