【摘要】 采用溶胶-凝胶法制备了Lu₂Si₂O₇∶Ce纳米晶,利用X射线衍射（XRD）、扫描电镜（SEM）、荧光光谱仪、X射线激发发射谱仪对制备的Lu₂Si₂O₇∶Ce纳米晶的晶相结构、微观形貌和光学性能进行了表征。结果表明,溶胶-凝胶法制备的Lu₂Si₂O₇∶Ce前驱体在煅烧温度为1 000℃时开始晶化,晶粒尺寸随着煅烧温度的升高而变大,1 200℃煅烧2 h后的晶体颗粒均匀,分散性最优,平均晶粒尺寸约为28.9 nm,呈近球形;Lu₂Si₂O₇∶Ce纳米晶的紫外吸收谱存在峰位分别为304 nm和350 nm两个吸收峰,源自于Ce³⁺离子的4f→5d跃迁;光致发射谱和X射线激发发射谱都表现为典型的非对称双峰结构,归属于Ce³⁺离子的5d¹→²F_5/2和5d¹→²F_7/2跃迁,Ce³⁺离子的最佳掺杂浓度约为1%;荧光衰减时间约为37.2 ns,可满足高时间分辨X射线探测需要。更多还原

【Abstract】 Cerium-doped lutetium pyrosilicate Lu₂Si₂O₇∶Ce nanocrystalline was synthesized by the sol-gel method. The structure, morphologies and scintillation properties of Lu₂Si₂O₇∶Ce nanocrystalline were characterized by X-ray diffractometer（XRD）, scanning electron microscope（SEM）, photoluminescence and X-ray excited luminescence. The results indicate that Lu₂Si₂O₇∶Ce starts to crystallize at about 1 000 ℃ and the crystallite size increases with the increasing calcining temperature. Well dispersed, homogeneous and near-spherical Lu₂Si₂O₇∶Ce powder with an average grain size about 28.9 nm was obtained after sintering at 1 200 ℃ for 2 h. The excitation spectrum consists of two intense broad bands at 304 nm and 350 nm, which are corresponding to the 4 f→5 d transition of Ce³⁺ ions. The emission peak under 350 nm and X-ray excitation both exhibit a typical asymmetric peak, which are attribute to 5 d¹→²F_5/2 and 5 d¹→²F_7/2 transition of the Ce³⁺ ions. The optimized doping concentration of Ce³⁺ ion is about 1%. The decay time of the as-prepared Lu₂Si₂O₇∶Ce phosphor is about 37.2 ns, which can satisfy the requirement of the X-ray detection with high time resolution.更多还原