Charge screening effects in the resonant photoemission of Rh 2 O 3 , RuO 2 , and MoO 2

We have performed valence-band resonant photoemission spectroscopy across the transition-metal (TM) L-3 edge of Rh2O3, RuO2, and MoO2. This technique allows us to access important information on the partial contribution of each respective TM. We show that an extended cluster model, coupled with transitions between discrete and continua states, describes well the overall resonance behavior as well as the experimental constant initial-state (CIS) spectra. Moreover, we analyze the resonant enhancement of the main lines and satellite structures to discuss the influence of the different charge regimes, the TM-O 2p hybridization, and additional charge screenings to the CIS signal. Finally, we argue that this approach can be extended to the study of other transition-metal oxides.