Magnetization of single-crystal erbium

We present the results of magnetization and ac-susceptibility measurements on single-crystal erbium along all three crystal axes. We observe antiferromagnetic ordering of the c axis and the basal-plane-moment components at 89 and 53 K, respectively. In addition, we observe anomalies at 51, 40, 34, 29, and 27 K. These anomalies in magnetization and ac-susceptibility data correspond to the commensurate spin-slip structures observed by Gibbs et al. in x-ray synchrotron scattering studies. In addition, we find that the basal-plane ordering at ${\mathit{T}}_{\mathit{N}\mathrm{\perp }}$=53 K takes place before any spin-slip transition appears as the temperature is lowered.