SURFACE-POLARITONS ON ANTIFERROMAGNETIC SUPERLATTICES

The effective-medium theory of magnetic superlattices is applied to uniaxial antiferromagnets without an external field. The effective magnetic permeability tensor is then diagonal but anisotropic. a surface polariton exists on a semi-infinite antiferromagnet/non-magnet superlattice; it has a magnetostatic limit if f1> 1 2, where f1 is the proportion of antiferromagnet, but is a virtual mode qithout a magnetostatic limit of f1 < 1 2. Calculations of attenuated-total-reflection spectra for the FeF2/ZnF2 system indicate that the surface polariton should be observable by this means. © 1990.