Gd~(3+)-sensitized Tb~(3+)-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+∶6P7/2 to Tb3+∶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.