Systematic Analysis of Core Photoemission Spectra for Actinide Di-Oxides and Rare-Earth Sesqui-Oxides

Abstract

We carry out systematic analysis of 4f core photoemission spectra for actinide di-oxides AnO 2 (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 PuO 2 , AmO 2 and CmO 2 . It is shown that PuO 2 and BkO 2 are strongly mixed valence compounds, and that a crossover between Mott-Hubbard-type and charge-transfer-type insulators occurs around NpO 2 . A previous analysis of 3d core photoemission spectra for rare-earth sesqui-oxides R 2 O 3 (R = La ∼ Yb) is briefly reviewed, and the results for AnO 2 and R 2 O 3 are compared