Faraday Effects of Tetrahedrally Coordinated Co₃⁺ in Magnetic Garnets

Abstract

Effects of spin-orbit interaction (S.O.) and S₄ low symmetry crystal field on the Faraday rotation spectra (FRS) of the tetrahedral Co³⁺ in magnetic garnets are investigated in the scheme of the crystal field theory. The FRS of the magnetic garnets containing tetrahedral Co²⁺ and Co³⁺ are also calculated. In order to explain the observed FRS of the tetrahedral Co³⁺, (1) the coefficient λ of S.O. having negative sign in the -100∼-160 cm^-1 range, and (2) a fairly large low-symmetry field are required.