Resonant x-ray emission spectroscopy at the L3 edge of americium up to 23 GPa

Resonant x-ray emission spectroscopy and x-ray absorption near-edge structure experiments have been performed on Am metal at the L3 edge as a function of pressure. The hypothesis that the Am valence change at high pressure is associated with a mixing of the 5 f6 and 5 f7 configurations, hybridized with the 6d valence band, is not substantiated by the experiments. Neither the measured resonant x-ray emission spectroscopy nor x-ray absorption near-edge structure exhibit additional features expected for mixed valence. Only a small shift ∼+2eV of the L3 edge energy position and a decrease in white line intensity at high pressure is observed. The experimental results at higher pressure may be reproduced by increasing the 6d bandwidth and occupation and increasing the 5f bandwidth without any change in occupation. Further progress should be directed toward experiments at the Am M edges to observe directly the 5f states. © 2010 The American Physical Society.