Resonant Photoemission Study of Molybdenum Bronzes: K0.3MoO3, K0.33MoO3and K0.9Mo6O17

Abstract

The electronic structures of molybdenum bronzes K _0.3 MoO ₃ , K _0.33 MoO ₃ and K _0.9 MoO ₁₇ have been systematically studied by means of the ultraviolet photoemission spectroscopy (UPS). Resonant photoemission spectra have been measured in the photon energy range from 32 eV to 100 eV. The measurements of total yield spectra have also been made on K _0.3 MoO ₃ and K _0.9 Mo ₆ O ₁₇ . Resonant enhancements of the photoemission have been observed in the valence and conduction bands with the contribution from the Mo 4d states for the excitation around h v =49 or 50 eV. It is found that the resonant effect is very weak for the structures at a binding energy E _B =4.6 eV for K _0.3 MoO ₃ , and K _0.33 MoO ₃ . The magnitude of these resonances corresponds to the local electronic densities of Mo 4d states at the corresponding E _B and can be qualitatively explained by the simple band structure model.