LUMINESCENCE PROPERTIES OF PR3+ IN CUBIC RARE-EARTH-OXIDES

Luminescence properties of Pr3+-doped C-type sesquioxides Ln2O3 (Ln = Sc, Y, Gd) have been investigated. In cubic Ln2O3, the rare earth ion Pr3+ occupies two different cation sites with site symmetry C2 and S6. For all three sesquioxides, pairs of two distinct emission and excitation spectra were recorded. Time-resolved spectroscopy was used to assign the spectra to the two cation sites. In both emission spectra of site C2 and site S6, only the electric dipole transition 1D2 --> H-3(4) of Pr3+ was observed. The spectroscopic results were correlated with structural data to clarify the luminescence mechanism in cubic rare earth oxides.