High-resolution angle-resolved photoemission study of UN and USb; Dual character of 5f electrons

We have performed high-resolution angle-resolved photoemission spectroscopy on UN and USb to study the electronic structure near the Fermi level (E-F) and the nature of U 5f electrons. We found that the pnictogen (N and Sb) p bands are fully occupied in contrast with Ce monopnictides and shows a goo d qualitative agreement with the band calculation by treating the U 5f stat es as bands. On the other hand. we have not observed dispersive U 5f bands near EF predicted by the band calculation, instead we found two non-dispers ive bands near EF, which are assigned as the 5f(2)-final-state multiplet in dicative of localized U 5f states. The intensity of multiplet structure is stronger in USb than in UN. These results indicate the dual character of U 5f electrons and its difference between USb and UN. (C) 2001 Elsevier Scien ce B.V. All rights reserved.