Gd3+-sensitized Tb3+-doped Scintillating Silicate Glasses

Gd3+-sensitized Tb3+-doped scintillating silicate glasses with Gd2O3 and Tb2O3 concentrations up to 45wt% were prepared. Effects of different Gd2O3 and Tb2O3 concentrations on the density, refractive index and luminescence properties under UV and X-ray excitations were investigated and the energy transfer mechanisms between Gd3+ and Tb3+ analyzed and discussed. The results show that, with the increasing concentrations of Tb3+ and Gd3+, a monotonic increase in the energy transfer efficiencies from Gd3+ |SUP>6P7/2 to Tb3+ |SUP>5H7 is observed followed by enhanced emissions centered at 620, 583, 541 and 496nm under 273nm UV excitation. However, with X-ray excitation, the incorporation of a large amount of Tb3+ weakens the luminescence emission due to the increase of point defects in glass.