Electromagnetic wave propagation in the uniaxial antiferromagnetic crystals FeF2, CoF2, and MnF2

✍ Scribed by J. Brandmüller; A. Lehmeyer; K. M. Häussler; L. Merten

• Publisher: John Wiley and Sons
• Year: 1983
• Tongue: English
• Weight: 284 KB
• Volume: 117
• Category: Article
• ISSN: 0370-1972
• DOI: 10.1002/pssb.2221170135

✦ Synopsis

Abstract

In the most general form the matter equations of electrodynamics contain the magneto‐electric tensor in addition to the electric and magnetic permeability tensor. By group‐theoretical methods, however, it is shown that for crystals belonging to the magnetic point group 4′/mmm′ the magneto‐electric tensor vanishes. Important examples for this point group are the antiferromagnets FeF~2~, CoF~2~, and MnF~2~. Regarding this essential simplification a generalized Fresnel's equation of the wave normals is derived for these antiferromagnetic crystals. The Fresnel's equation has two solutions describing the magnitudinal and directional dispersion of the refractive index for the two corresponding waves. The limiting cases of these two solutions agree with results already known from literature. Besides, the polarization of both waves is determined.