Band structure and fermi surface of uranium compounds; Soft X-ray angle-resolved photoemission study

Fujimori, Shinichi   ; Terai, Kota; Takeda, Yukiharu   ; Okane, Tetsuo  ; Saito, Yuji  ; Kobayashi, Keisuke; Fujimori, Atsushi; Yamagami, Hiroshi*; Ikeda, Shugo; Matsuda, Tatsuma; Haga, Yoshinori   ; Yamamoto, Etsuji  ; Onuki, Yoshichika

In the present study, we have performed SX-ARPES experiments on some heavy Fermion (HF) uranium compounds such as UPdAl using soft X-ray synchrotron radiation from BL23SU of SPring-8. UPdAl is an HF uranium compound which has transitions into an antiferromagnetic phase at K and into a superconducting phase at =2 K. To describe the various properties of this compound, the dual model for U 5 states is proposed. In this model, two of the three U 5f states are in a localized state while the third electron has delocalized character. We have obtained U 5f sensitive band structure of UPdAl by SX-ARPES, and the results are compared with this scenario. Temperature dependence of the U 5 electronic structure in this compound is also discussed.