Possibility of Visual Observation of Antiferromagnetic Domains

The optical properties of magnetic materials are studied using symmetry considerations. It is found that in addition to birefringence, Faraday rotation, and optical activity there should exist another effect, namely gyrotropic birefringence. This birefringence is of opposite sign for magnetic domains related to each other by time reversal, and can, therefore, in principle be used for observation of antiferromagnetic domains so related. The dependence of the optical properties on external agents such as electric and magnetic fields and stress is also considered.