Abstract
A neutron diffraction study of nickel oxide was performed utilizing single crystal samples to investigate the magnetic structure. The results indicate the structure to have a single magnetic axis lying in a (111)plane, but within this plane there are domains such that the directions of the moments of these domains are distributed symmetrically. To fit the data required an effective spin value for the Ni++ atom of 0.8 and an isotropic form factor exp[−6(sinθ/λ)2].