Analysis of the Spectra of Triply Ionized Iron in Rare-Earth Aluminum Garnets

摘要

Recent successes in transferring energy from excited chromium ions to neodymium ions in gadolinium scandium gallium garnets have increased interest in the spectra of transition-metal ions in potential laser host materials. In particular, the garnet materials, which can be doped with both rare-earth and transition-metal ions, are possible candidates for such a laser. In the work reported here, we analyze the spectra of Ferric ions in the rare earth aluminum garnets, Gadolinium, Terbium, Dysprosium, Holmium ions, Erbium, Thulium and Ytterbium. The Fe3+ ion is assumed to occupy the site with Cubic symmetry. The reported analysis of the experimental data assumes cubic symmetry and gives the usual parameters for the free ion and the crystal field. Using the known crystallographic data we then compute the crystal field components. The concept of rotational invariance is used to obtain an estimate of the radial integrals needed to convert the crystal field components to the crystal field parameters. The resulting crystal field parameters are used to calculate the energy levels of Fe3+ in the entire series, including lutetium.