Terbium-activated heavy scintillating glasses

Tb-activated scintillating glasses with Ln2O3 (Ln=Y, Gd, Lu) concentrations up to 40 mol% have been prepared. The effects of Ln3+ ions on the density, thermal properties, transmission, and luminescence properties under both UV and X-ray excitation have been investigated. Glasses containing Gd2O3 or Lu2O3 exhibit a density of more than 6.0 g/cm3. Energy transfer from Gd3+ to Tb3+ takes place in Gd-containing glass and as a result the Gd-containing glass shows a light yield 2.5 times higher than the Y- or Lu-containing glass. The effect of the substitution of fluorine for oxygen on the optical properties was also investigated.