Electrical and Magnetic Properties of CeAu2Si2

We succeeded in growing a high-quality single-crystal of CeAu 2 Si 2 , which was previously reported to be highly sample-dependent in terms of electrical and magnetic properties. CeAu 2 Si 2 is not a simple AF1-type antiferromagnet, but reveals three antiferromagnetic transitions in a narrow temperature range from the Neel temperature T N1 =9.6 K to T N3 =8.0 K. A clear metamagnetic transition with two steps was observed at H c1 =53 kOe and H c2 =55 kOe in the magnetization curve below 5 K for the magnetic field along an antiferromagnetic easy-axis, namely, the tetragonal [001] direction, with a saturation moment of 1.53 µ B /Ce. The magnetic susceptibility and magnetization are anisotropic, which are well explained by results of crystalline electric field analyses. We also studied the de Haas–van Alphen (dHvA) effect. The detected dHvA branches are found to be consistent with those of a non-4 f reference compound such as YCu 2 Si 2 .