Stephen L. Dole

Optical absorption spectrum of trivalent cerium in Y 2 O 3 , Ba 2 GdTaO 6 , ThO 2 , and related compounds

The optical absorption coefficient at room temperature has been measured for cerium-doped Y2O3 and Y1.4Gd0.6O3 samples from 1500 to 45000 wave numbers. Diffuse reflectivity has been measured on cerium-doped powders of Y2O3, Lu2O3, Sc2O3, Ba2GdTaO6, and ThO2 over the same range. A number of 4f − 4f and 4f − 5d transitions of trivalent Ce have been seen, and some experimental values for their oscillator strengths have been determined. A tentative assignment of particular transitions to either C2 or C3i sites in the Y2O3 structure has been made. Some of the transitions have also been seen by use of Raman scattering. Several phonon replicas of the 4f − 4f transitions have been identified. The charge-transfer band of tetravalent cerium in Y1.4Gd0.6O3 has been identified.