Antiferromagnetic and ferromagnetic phases of [formula omitted

Abstract

We have succeeded in growing a high-quality single crystal of UCu 2 Si 2 with a tetragonal structure by the Sn-flux method and measured the magnetic susceptibility and magnetization. UCu 2 Si 2 is confirmed to order antiferromagnetically below T N = 106 K , and follows a successive ferromagnetic ordering at T C = 100 K . The magnetic properties are highly anisotropic, reflecting the crystal structure. An easy-axis of magnetization is found to be the [0 0 1] direction ( c-axis), while the [1 0 0] direction ( a-axis) corresponds to the hard-axis in magnetization. The saturation moment is determined as 1.8 μ B / U .