Critical view on luminescence properties of Y 2O 3:Eu 3+ after dispersion in SiO 2

Improvement of luminescence intensity of material by core-shell formation or dispersion in another matrix was reported in literature. In this direction, we have prepared Y₂O₃:Eu³⁺ particles dispersed in SiO₂. However, their luminescence intensities are less than Y₂O₃:Eu³⁺ due to non-radiative process arising from association of amorphous silica and Si-O-H. Variation of luminescence intensity is described in terms of site symmetry, heat-treatment effect and surrounding medium. Intensity of electric dipole transition is more than that of magnetic dipole transition for samples heated up to 1100 °C. For higher heated sample at 1300 °C, the opposite effect is found. This is explained on the formation of new triclinic phase α-Y₂Si₂O₇.