THE THEORY OF FAR-INFRARED OPTICS OF LAYERED ANTIFERROMAGNETS

We present a full theoretical discussion of the surface polaritons, ATR and oblique incidence reflectivity spectra of layered antiferromagnets. The results apply equally to a large class of easy-plane magnetic systems including artificial magnetic superlattices with antiferromagnetic coupling. It has recently been argued that the conventional calculation of the RF permeability tenser mu is incorrect and should be replaced by a calculation that is consistent with macroscopic electrodynamics. Our computed spectra for NiO lead to the conclusion that the form of mu can be established by comparison with experimental far-infrared spectra.