实验制备了以Tb^3+为激活剂、Gd^3+为敏化剂的硅酸盐闪烁玻璃,研究了Tb2O3和Gd2O3含量对玻璃密度和玻璃折射率,以及对玻璃在紫外光激发和X射线激发条件下的光学光谱特性的影响.通过研究Tb^3+/Gd^3+共掺闪烁玻璃的激发与发光特性、荧光寿命,结合稀土离子能级结构,分析了Gd^3+→Tb^3+离子之间的能量转移与传递机制.结果表明:在紫外激发条件下,大量引入Tb2O3和Gd2O3可提高Gd^3+→Tb^3+离子之间的能量传递效率,有利于Tb^3+离子的绿色发光; 但是在X射线激发条件下大量引入Tb^3+离子,由于缺陷数增加而弱化Tb^3+离子荧光.
Gd^3+-sensitized Tb^3+-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 Gd^3+ and Tb^3+ analyzed and discussed.The results show that,with the increasing concentrations of Tb^3+ and Gd^3+,a monotonic increase in the energy transfer efficiencies from Gd^3+∶6P7/2 to Tb^3+∶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 Tb^3+ weakens the luminescence emission due to the increase of point defects in glass.