Magnetooptical method of investigation of the magnetic inhomogeneity of easy-plane antiferromagnets with a weak ferromagnetism

A method for determining the spatial orientation of the local vector of spontaneous magnetization in low-symmetry magnets with the easy-plane anisotropy is described that is based on the combination of magnetooptical visualization and computer processing of the observed images of magnetic inhomogeneity of the medium. The possibility of using this method to determine the structure of weak ferromagnets in both the ground state and modulated magnetic phase is illustrated on the example of the rhombohedral FeBO₃:Mg crystal.