Local and electronic structure of Am2O3 and AmO2 with XAFS spectroscopy

XAFS studies were performed in a study of americium sesquioxide (Am2O3) with A-type rare earth oxide structure and americium dioxide (AmO2) with fluorite structure. EXAFS results on the Am-LIII absorption edge of Am2O3 and AmO2 were in good agreement with crystallographic data resulting from X-ray diffraction analysis. Theoretical assignments were performed using the all-electron Full Potential Linearized Augmented Plane Wave (FP-LAPW) method in characterizing XANES with regard to the electronic structure of Am2O3 and AmO2. The theoretical XANES spectra of Am2O3 and AmO2 well reproduced the experimental ones. In addition, it was found that the white line peak was created due to the interaction between the Am-d and O-p components, and the broad peak and the tail peak were created due to the interaction between the Am-d and O-d components.