Fermi surface properties of ferromagnet UCuSi

Matsuda, Tatsuma; Ikeda, Shugo*; Yamamoto, Etsuji  ; Haga, Yoshinori   ; Shishido, Hiroaki*; Yamagami, Hiroshi; Settai, Rikio*; Onuki, Yoshichika

We have succeeded in growing a high-quality single crystal of UCuSi with the tetragonal structure by the Sn-flux method and measured the de Haas-van Alphen effect. UCuSi orders antiferromagnetically below = 106 K, and follows a successive ferromagnetic ordering at = 100 K. Several de Haas-van Alphen branches are observed in the ferromagnetic state, ranging from 510 to 710 Oe. The corresponding cyclotron effective masses are moderately large, ranging from 1.4 to 4.2 , consistent with the electronic specific heat coefficient = 20 mJ/Kmol. These experimental results are approximately explained by the 5-itinerant spin- and orbital-polarized energy band model.