Electronic structures of UTSn (T=Ni, Pd) using photoemission spectroscopy

Electronic structures of UTSn (T = Ni, Pd) have been investigated using photoemission spectroscopy (PES). The extracted U 5f PES spectra of UTSn (T = Ni, Pd) exhibit a broad peak centred at eV below EF with rather small spectral weight near EF (Nf(EF)). The small Nf(EF) in UTSn is found to be correlated with the T d PES spectra that have a very low density of states (DOS) near EF. The temperature-dependent high-resolution PES spectra of UTSn provide evidence for the V-shaped reduced metallic DOS near EF, but they reveal no appreciable changes in their electronic structures across the magnetic phase transition temperatures. Comparison of the measured PES spectra to the LSDA +U band structure calculation shows reasonably good agreement for UPdSn, but not for UNiSn. Therefore, in contrast to the general consensus of the localized U 5f electrons in UTSn (T = Ni, Pd), our finding supports a rather itinerant nature of U 5f electrons for UPdSn, but not for UNiSn.