Antiferromagnetic and ferromagnetic phases of UCu2Si2

We have succeeded in growing a high-quality single crystal of UCu2Si2 with a tetragonal structure by the Sn-flux method and measured the magnetic susceptibility and magnetization. UCu2Si2 is confirmed to order antiferrornagnetically 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 [001] direction (c-axis), while the [100] direction (a-axis) corresponds to the hard-axis in magnetization. The saturation moment is determined as 1-8 mu(B)/U (c) 2005 Published by Elsevier B.V.