Electrical and magnetic properties of a single crystal UCuSi

Matsuda, Tatsuma; Haga, Yoshinori   ; Ikeda, Shugo; Galatanu, A.; Yamamoto, Etsuji  ; Shishido, Hiroaki*; Yamada, Mineko*; Yamaura, Junichi*; Hedo, Masato*; Uwatoko, Yoshiya*; Matsumoto, Takuya*; Tada, Toshiya*; Noguchi, Satoru*; Sugimoto, Toyonari*; Kuwahara, Keitaro*; Iwasa, Kazuaki*; Kogi, Masafumi*; 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 electrical resistivity, magnetic susceptibility, magnetization and specific heat. UCuSi is found to order antiferromagnetically below = 106 K, and follows a successive ferromagnetic ordering at = 100 K. The magnetic properties are highly anisotropic, reflecting the crystal structure. An easy-axis of magnetization is found to be the [001] direction (-axis) both in the antiferromagnetic and ferromagnetic phases, while the [100] direction (-axis) corresponds to the hard-axis in magnetization. The magnetization curve in the antiferromagnetic phase indicates a clear metamagnetic transition at a low field of about 1 kOe and changes smoothly into a ferromagnetic magnetization curve below = 100 K. The saturation moment is determined as 1.75/U at 2 K. The electronic specific heat coefficient is also determined as 20 mJ/Kmol.