Li6Gd(BO3)3:Ce晶体的提拉法生长和闪烁性能
Czochralski Growth and Scintillation Properties of Cerium-doped Li6Gd(BO3)3 Crystals
Received date: 2006-01-05
Revised date: 2006-02-23
Online published: 2006-09-20
采用提拉法和铂坩埚感应加热技术生长出最大尺寸为直径25mm, 长40mm的Li6Gd(BO3)3:Ce晶体. XRD分析表明, 生长出的晶体为单一的Li6Gd(BO3)3:Ce相, 结构属P21/c空间群. 对晶体生长中存在的解理开裂、应力开裂及多晶问题进行了讨论, 并从晶体结构的角度解释了(020)完全解理面出现的原因. 晶体在380~800nm之间的透过率接近90%, 200~380nm之间的吸收是由Ce3+离子的4f-5d跃迁和Gd3+离子的4f-4f跃迁引起的. 不同激发源激发下的发射均显示Ce3+离子的双谱峰特征; 相比于紫外激发下的发射而言, X射线激发下的发射光谱略有红移. 该晶体发光符合单指数衰减模型, 衰减时间为30.74ns在241Am源的α射线激发下晶体的能量分辨率为28.84%.
陈俊锋 , 李 赟 , 宋桂兰 , 姚冬敏 , 袁兰英 , 齐雪君 , 王绍华 . Li6Gd(BO3)3:Ce晶体的提拉法生长和闪烁性能[J]. 无机材料学报, 2006 , 21(5) : 1053 -1059 . DOI: 10.3724/SP.J.1077.2006.01053
Cerium-doped lithium gadolinium borate (Li6Gd(BO3)3:Ce) single crystals up to 25mm in diameter and 40mm in length were grown by the Czochralski method using inductively heated platinum crucibles. The as-grown Li6Gd(BO3)3:Ce crystals are of single-phase and they belong to the monoclinic system with space group of P21/c. Problems existing in crystal growth such as cleavage crack, stress crack and polycrystalline were discussed. The appearance of the perfect cleavage plane (020) was explained by considering the structure of Li6Gd(BO3)3. The results show that optical transmittance in the range of 380~800nm is near 90%. The absorption from 200nm to 380nm can be related to 4f-5d transitions of Ce3+ ions and 4f-4f transitions of Gd3+ ions. Both the mission under the optical excitation and the emission under X-ray excitation display the typical double-peaks characteristic of Ce3+ ions. Compared with the emission under the optical excitation, the emission under X-ray excitation shows a slight ‘red shit’. Decay time spectrum from Li6Gd(BO3)3:Ce can be well fitted with a decay time of 30.74ns. The energy resolution under the excitation of α-ray from 241Am measured is 28.84%.
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