A magnetooptical study of the odd crystal field component in a terbium-yttrium aluminum garnet

We have studied the photoluminescence spectra and the luminescence magnetic circular polarization (LMCP) spectra in the region of the 4f-4f radiative transition ⁵D₄→⁷F₆ in the rare earth Tb³⁺ ion in a Y₃Al₅O₁₂ garnet matrix. A comparison of the experimental and theoretically calculated LMCP spectra allowed parameters of the odd crystal field component to be determined that removes the prohibition with respect to parity from the 4f-4f transitions in Tb³⁺ ion in the garnet structure. The energy spectra and wave functions of ⁵D₄ and ⁷F₆ multiplets of Tb³⁺ ion in a crystal field with the D₂ symmetry have been calculated.