Single crystal neutron diffraction studies of antiferromagnets at low temperatures in applied magnetic fields

The magnetic properties of a number of hexagonal layer-type compounds have been investigated by single crystal neutron diffraction methods at temperatures down to 1.35 °K and with magnetic fields up to 16.3 kOe applied to the sample. The antiferromagnetic structure of MnBr2 (TN = 2.16 °K) and its related domain transformation properties, and the effect of an applied magnetic field on the antiferromagnetic structure of FeCl 2 (TN = 23 °K) are described in some detail as illustrations of the techniques. Results for the anhydrous dibromides and dichlorides of Mn, Fe, and Co are summarized briefly.