Resonant Raman scattering at theLthresholds with final 3shole in 3d2+systems. II. The CoO case in the wholeL2,3region

Abstract

We present experimental and theoretical results on CoO resonant Raman scattering (RRS) with excitation at many values in the whole ${\mathrm{Co}}^{2+}{\ensuremath{-}L}_{2,3}$ region, and with a final state containing a $\mathrm{C}\mathrm{o}\ensuremath{-}3s$ hole. The theory includes the final-state interaction between the configurations with one $3s$ hole and that with two $3p$ holes [configuration interaction (CI)]. A cluster calculation with CI reproduces the experimental results with excitation spanning the whole ${L}_{3}$ region. In the ${L}_{2}$ region the theory reproduces the evolution of the RRS doublet at higher outgoing energy. On this basis the role of CI and of the ligand hole effects are discussed vs the excitation energy. At least 5 eV above the ${L}_{3}$ threshold, the experimental results show also a nondispersive component, with the intensity rapidly increasing with the excitation energy. The position and shape of this component are well reproduced by a model calculation accounting for all possible partitions between the transitions to the continuum and to the $3d$ shell. However, the intensity of the calculated nondispersive component is about an order of magnitude smaller than the measured one. The implications of this fact in terms of the dynamics of the intermediate state are outlined.