X射线荧光粉Gd2O2S:Pr,Ce的固相合成及发光性能研究

采用草酸铵共沉淀法实现在Gd2O3中掺杂Pr和Ce,以此为原料,硫粉为硫化剂,无水Na2CO3为助熔剂,1000℃真空固相合成了Gd2O2S:Pr和Gd2O2S:Pr,Ce粉末。采用XRD确认了反应产物为目标产物,制备的Gd2O2S:Pr为六方晶系单一相,粉末粒度分布1~10μm,在313 nm的紫外光激发下,主发射峰位于511 nm,属于Pr3+的3P0→3H4跃迁。主发射光强度随Pr3+的含量变化而改变,当Pr3+的含量在0.80%时主发射光强度最大。添加Ce3+可以明显降低Gd2O2S:Pr的荧光余辉,但同时也降低了发射光强度,Ce3+的添加量要在余辉控制,荧光光强和闪烁体使用寿命三者间平衡选择。

Solid phase synthesis and luminescence properties of X-ray phosphor powder Gd2O2S:Pr,Ce

Using Gd2O3:Pr,Ce synthesized by ammonium oxalate coprecipitation method as a raw material,sulfur as a vulcanizing agent and anhydrous Na2CO3 as a fluxing agent,Gd2O2S:Pr and Gd2O2S:Pr,Ce were prepared by solid phase method at 1000°C in vacuum atmosphere.XRD confirmed that the reaction product was the target product.The prepared Gd2O2S:Pr was a hexagonal single phase with a particle size distribution of 1μm-10μm.Under the excitation of 313 nm ultraviolet light,the main emission peak was at 511 nm,which belonged to the 3P0→3H4 transition of Pr3+.The intensity of the main emission light changed with the content of Pr3+.When the content of Pr3+was 0.80%,the main emission intensity was the largest.The addition of Ce3+could significantly reduce the fluorescence afterglow of Gd2O2S:Pr,but reduce the intensity of emitted light at the same time.The amount of Ce3+added should be balanced between afterglow control,fluorescence intensity and lifetime of scintillator.