利用多坩埚温度梯度法生长了PbWO_4和BaF_2:PbWO_4晶体,研究了PbWO_4、退火PbWO_4和BaF_2:PbWO_4晶体的透过光谱和X射线激发光谱,结果发现这些光谱性质与晶体的组成和生长工艺密切相关,其中退火的影响较复杂.高温退火的PbWO_4晶体的透过光谱在360nm以上波段有较好的透过率,但是在320-360nm波段透过率反而略有降低;380nm以上波段的X射线激发光谱光谱强度较高,320～380nm波段光谱强度却略有降低.掺杂的离子改善了晶体的透过率和x射线激发发光光谱强度.利用晶体的生长工艺和组成与缺陷以及晶体光学性质之间的关系解释了这些现象产生的原因.BaF_2:PbWO_4掺杂晶体的X射线激发光谱的波形和发光峰强度均发生了很大程度的改变,与F-离子掺杂引发晶体[WO_4]~(2-)四面体基团畸变而产生的新的发光中心有关.%PbWO_4 and BaF_2 :PbWO_4 were grown by multi-crucible temperature gradient system.The transmittance spectra and x-ray excited luminescence spectra of as-grown PbWO_4, annealed PbWO_4 and annealed BaF_2: PbWO_4 were studied.The results reveal that these properties are related to the composition and growth arts of the crystals.The facts are complicated for the crystals annealing.In the wavelength range above 360nm,the transmittance for the annealed crystal is better than that of the as-grown crystal, while it is a little weaker than that of the as-grown crystal in the wavelength range of 320 ～360nm.For the x-ray excited luminescence spectra, the spectrum intensity of the annealed crystal is higher than that of as-grown crystal in the wavelength range above 380nm, while it is a little weaker than that of as-grown crystal in the wavelength range of 320～380nm.The doping ions improve the transmittance and the x-ray excited luminescence spectrum intensity.These phenomena are explained based on the relations of the defect, crystal growth arts and the optical properties of these crystals.For the BaF_2:PbWO_4 crystal, it' s peak shape and intensity of x-ray excited luminescence spectrum are evidently changed than PbWO_4 crystal.The phenomenon may relate to the fact that [WO_4]~(2-) tetrahedron of the crystal is degenerated when it is doped with F~- ions, and the degeneration will induce a new luminescent center.
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