Magnetic properties of a GdMn6Sn6 single crystal

The magnetization of a GdMn 6 Sn 6 single crystal has been measured in static magnetic fields up to 14 T as well as in pulsed fields up to 60 T. The easy magnetization direction has been confirmed to lie in the basal plane of the hexagonal crystal, the anisotropy within the plane being negligible. However, our data do not corroborate the earlier assertion that GdMn 6 Sn 6 is a collinear ferrimagnet. This disagrees with the observed field dependence of magnetization along the easy direction as well as with the temperature dependence of spontaneous magnetization. A way out of the contradiction is to admit that GdMn 6 Sn 6 has a more complex, non-collinear magnetic structure.