Energy Levels and Crystal-Field Calculations of Europium and Terbium in Yttrium Aluminum Garnet

Experimental and theoretical studies of the trivalent europium and terbium ions in yttrium aluminum garnet are reported in this communication. From crystal-field calculations on the split ${}_{}{}^7{}_{}{}^{}F$ manifolds of ${\mathrm{Eu}}^{3+}$ and ${\mathrm{Tb}}^{3+}$, it is concluded that the crystal field is approximately tetragonal. Agreement between experimental and calculated splitting patterns is satisfactory for those Stark components of ${}_{}{}^7{}_{}{}^{}F$ manifolds which are not far removed from the center of gravity.