Actinide Response under Pressure Probed by Inelastic X-ray Scattering

ABSTRACTThe electronic response of actinide systems under high-pressure conditions is undoubtedly of broad scientific interest but simultaneously very difficult to qualify. We will focus here on the use of inelastic x-ray scattering and its significance for actinides research through recent examples. IXS indeed combines several advantages that turn it into a powerful probe of the electronic and valence properties of f-electron systems. Besides element and orbital selectivity, resonant IXS can overcome core-hole lifetime broadening thus providing sharper spectral features and finer details about the electronic structure. Second, non-dipolar transitions are allowed in non-resonant IXS at high momentum transfer; thus “giant dipolar” Fano-like resonances that overwhelms the electron response at the O4,5 edges can be avoided. Recent results of IXS under pressure in Am and U under pressure are presented along with perspectives for actinides research at SOLEIL synchrotron.