Systematic analysis of core photoemission spectra for actinide di-oxides and rare-earth sesqui-oxides

We carry out systematic analysis of 4f core photoemission spectra for actinide di-oxides AnO2 (An=Th∼Bk), using the impurity Anderson model including the exchange interaction J between 5f electrons. The effect of J is important in explaining the observed photoemission spectra especially for PuO2, AmO2 and CmO2. It is shown that PuO2 and BkO2 are strongly mixed valence compounds, and that a crossover between Mott-Hubbard-type and charge-transfer-type insulators occurs around NpO2. A previous analysis of 3d core photoemission spectra for rare-earth sesqui-oxides R2O3(R=La∼Yb) is briefly reviewed, and the results for AnO2 and R2O3 are compared. (author)