【摘要】 用多坩埚温度梯度系统生长了一批不同掺杂浓度的BaF2:PbWO4晶体,研究了这些晶体的透过光谱、x-射线激发光谱(XEL)与晶体掺杂浓度的关系,结果发现合适浓度的掺杂增加了晶体的透过率、XEL光谱强度,并使XEL光谱峰红移.当掺杂浓度1000mol-ppm浓度时,晶体的透过率明显增大、XEL光谱强度明显增强.当掺杂浓度达到2500～3000mol-ppm左右时,透过率和x-射线激发光谱强度有大幅度升高.BaF2浓度的继续增加到3500mol-ppm浓度时,晶体透过率变化不大,但是XEL光谱强度降低,波峰加宽,继续增加掺杂浓度.掺杂浓度5000mol-ppm时,波峰发生分裂,变成一个蓝光峰和绿光峰,蓝光峰很低,绿光波峰强,晶体光透过率降低.研究了这些现象发生的原因,发现晶体中V3Pb+缺陷和VO-缺陷、晶体[WO3F]-四面对闪烁发光的增强作用和间隙钡,间隙氧以及[WO2F2]四面体对闪烁发光的减弱作用与这些现象密切相关.更多还原

【Abstract】 A batch of BaF2:PbWO4 crystals are grown up by a multi-crucible temperature gradient system.The transmittance and x-ray exciting luminescence(XEL) spectra of these crystals were studied.The results reveal that these scintillation properties are strikingly effected by the doped BaF2 content in the crystals.Proper BaF2 content in the crystal could improve the transmittance and the XEL peak intensity and make the XEL peaks shift to longer wavelength.For the crystal grown up from the melt with BaF2 1000mol-ppm,this raising extent becomes evident for their transmittance and the XEL peak intensity.For the crystal grown up from the melt with BaF2 2500～3000mol-ppm,their transmittance and XEL peak intensity raise greatly.For the crystal grown up from BaF2 3500mol-ppm,there is no evidence change for the transmittance,but its blue XEL peak intensity becomes weak and the peak width enlarged.For the crystal grown up from the melt with BaF2 5000mol-ppm,the blue peak intensity becomes low while the green peak intensity becomes strong.The enhancing-effect of V3+Pb and VO-and-tetrahedron and the weakening-effect of O ·i,Ba¨i and tetrahedron are related to the phenomena.更多还原