生长温度梯度对Bi_4Ge_3O_(12)晶体辐照损伤的影响  

Influence of Temperature Gradient on Radiation Damage of BGO Crystals

作　　者：肖海斌[1] 胡关钦[1] 徐力[1] 

机构地区：[1]中国科学院上海硅酸盐研究所,上海201800

出　　处：《无机材料学报》2003年第2期470-474,共5页Journal of Inorganic Materials

摘　　要：研究了两类不同条件下生长的Bi_4Ge_3O_(12)晶体紫外辐照前后的光学透射谱和能量分辨率,研究结果指出:第一类晶体(高温度梯度生长)经紫外辐照后,在480nm透过率有明显下降(20％以上),能量分辨率也明显变差(改变5％以上).而第二类晶体(低温度梯度生长)经紫外辐照后,其透射谱以及能量分辨率基本不变.从晶体缺陷角度讨论了造成两类不同晶体抗辐照性能存在差别的原因.In this work, we grew two types of Bi4Ge3O12 (BGO) crystals in different temperature gradient by Bridgmen-Stockbarger technology and compared the optical transmissions and energy resolutions of the two types of BGO crystals before and after ultraviolet irradiation. It was found that the optical transmissions and energy resolutions of the two types of BGO crystals are similar before UV-irradiation. After UV-irradiation the optical transmissions at 480nm of the first type of BGO crystals which were grown in high temperature gradient cut down about 20% and their energy resolutions obviously changed bad from about 12% to 18%. But the optical transmissions and energy resolutions of the second type of BGO crystals which were grown in low temperature gradient keep unchanged on the whole. After 250 degreesC/4h annealing, the optical transmissions and energy resolutions of the second type of BGO crystals can completely be recovered. Whereas the optical transmissions and energy resolutions of the first type of BGO crystals can't completely be recovered until through 800degreesC/8h annealing. The thermoluminescence curves of the two types of BGO crystals show that there is a luminescence peak at 85degreesC for second type of BGO crystal, whereas for the first type of BGO crystals, besides at 85degreesC, there are also two luminescence peaks at 130degreesC and at 170degreesC which may show that there exist defects with deeper traps in the first type of BGO crystals. The reason for the difference between the first and second type of BGO crystals may be that if the temperature drop dawn too fast during crystal growing, the defects in the melt can not spread out to the surface and so the defects easily exist in the first type of BGO crystals.

关 键 词：Bi4Ge3O12晶体 温度梯度 辐照损伤 能量分辩率 

分 类 号：O78[理学—晶体学]