Magnetic Structure of NiCl2·6H2O

Abstract
Neutron diffraction data of NiCl2·6H2O have been taken at 1.5° and 4.2°K on the (h0l) zone. The magnetic reflections observed at both temperatures indicate that the magnetic structure consists of antiferromagnetic (001) planes, with an antiferromagnetic coupling between planes, to give a magnetic cell with cm = 2c. Using the results of the NMR experiments, the magnetic space group is concluded to be Ic2/c. A study of the relative intensities of the magnetic reflections indicates that the spin direction is not along the a′ axis as has previously been assumed, but is approximately 22.5° from the a′ axis toward the a axis.