Electronic structure of actinide antimonides and tellurides from photoelectron spectroscopy

Single crystals of USb, NpSb, PuSb, UTe, NpTe and PuTe were investigated by photoelectron spectroscopy, this included angular-resolved studies on the U compounds. The spectral features show little dependence on incident photon energy, suggesting they all contain comparable amounts of 5f and conduction character. In the case of USb interesting (and unexpected) momentum dependent effects are observed in the angular-resolved studies. In PuTe, we confirm the presence of a strong three-peak structure near E-F, which has been interpreted as the signature of an intermediate valence state in similar materials. Hybridization of the 5f electrons with the conduction band is found within the series and the level of localization is shown to increase from Te to Sb. A surprising correlation between the binding energy of the peak bearing most of the 5f weight in the photoemission spectrum and the magnetic moment is discovered within the series, for which some explanations are suggested.