Effect of Mg 2+ and Ti IV doping on the luminescence of Y 2O 3:Eu 3+

Abstract

The Y 2O 3:Eu 3+,Mg 2+,Ti IV materials ( x Eu: 0.02, x Mg: 0.08, x Ti: 0.04) were prepared by solid state reaction. The purity and crystal structure of the material was studied with the X-ray powder diffraction. Luminescence properties were studied in the UV–VUV range with the aid of synchrotron radiation. The emission of Y 2O 3:Eu 3+,Mg 2+,Ti IV had a maximum at 612 nm ( λ exc: 250 nm) due to the 5D 0→ 7F 2 transition of Eu 3+. The excitation spectra ( λ em: 612 nm) showed a broad band at 233 nm, due to the charge transfer transition between O 2− and Eu 3+, and at 297 nm due to the Ti→Eu 3+ energy transfer. Only very weak persistent luminescence was discovered. In the room and 10 K temperature excitation spectra, the line at 208 nm is due to the formation of a free exciton (FE) and a broad band at 199 nm was related to the valence-to-conduction band absorption of the Y 2O 3 host lattice. The absorption edge was ca. 205 nm giving 6.1 eV as the energy gap of Y 2O 3.