EPR of Ferric Ions in Sodium Alum

余健治(Jiang-Tsu Yu)

《Chinese Journal of Physics》 19卷4期 (1981/12) Pp. 113-121

並列摘要

The EPR of single crystals of sodium aluminum alum doped with ferric ions were studied at room temperature. The resonance linewidths are relatively narrow and the fine structures well resolved. The ferric ions are found to occupy sites of trigonal symmetry. There are four chemically equivalent but magnetically non-equivalent sites of ferric ions in the crystal. The trigonal axis for each each site is along one of the 〔111〕 directions of the crystal lattice. The crystal field splittings are much larger than those in rubidium and potassium alums. The axial component of the crystal field is much larger than the cubic component for ferric ions in sodium alum. The second-order perturbation theory, which is usually good for S-state- ions, is not applicable for ferric ions in sodium alum. The Zeeman levels of ferric ions must be solved by finding the eigenvalues of a six by six matrix. The best-fit spin Hamiltonian parameters are g=2.007, D/gβ=390 gausses, α/gβ=35 gausses and F/gβ=-91 gausses.