ELECTRONIC-STRUCTURES OF PURPLE BRONZE KMO6O17 STUDIED BY X-RAY PHOTOEMISSION SPECTRA

X-ray photoemission spectroscopy study has been performed for the purp le bronze KMo6O17. The structures of conduction band and valence band are analogous to the results of ultraviolet photoemission spectra and are also consistent with the model of Travaglini el al., but the gap b etween conduction and valence band is insignificant. The shape of asym metric and broadening line of 0-1s is due to unresolved contributions from the many inequivalent oxygen sites in this crystal structure. Mo 3d core-level spectrum reveals that there are two kinds of valence sta tes of Molybdenum (Mo +5 and Mo +6). The calculated average valence st ate is about +5.6, which is consistent with the expectation value from the composition of this material. The tail of Mo-3d spectrum toward h igher binding energy is the consequence of the excitation of electron- hole pairs with singularity index of 0.21.