【摘要】 采用液相共沉淀方法并在不同烧结温度下制得了Eu:GGG荧光粉体。用X射线衍射分析了样品的结构,计算了其晶格常数,为1.2371nm。室温下,测量了Eu:GGG的光致发射光谱、激发光谱和荧光衰减曲线。激发光谱在波长240～287nm的谱带内和393nm处有强的激发,分别来自于Eu3+-O2-间的电荷迁移态吸收和Eu3+的7F0→5L6的跃迁吸收,同时在274nm处也出现了Gd3+的8S7/2→6IJ的特征吸收。393nm激发下,591nm处的发射峰最强,对应Eu3+的5D0→7F1的磁偶极跃迁,可能由于部分Eu3+处于反演中心对称格位所致。随着烧结温度升高,Eu:GGG的发光强度增强,这可能由于随着烧结温度升高,样品晶粒尺寸变大,单位体积内被激发的Eu3+离子数增加引起,而591nm发光的荧光寿命变短,可能是由Eu3+离子的能量共振传递过程中发光被陷阱捕获所致。更多还原

【Abstract】 Eu:GGG phosphors were prepared by co-precipitation method and sintered at different temperatures.The structure was analysed by X-ray diffraction and the lattice constant was calculated,which was 1.2371 nm.Emission,excitation spectra and fluorescence decay curve were measured at room temperature.There was a strong excitation band from 240 to 287 nm and a peak at 393 nm,and they were from the charge transfer absorption of Eu3+-O2-and the 7F0→5L6 transition absorption of Eu3+,respectively.The peak of 274 nm in the excitation spectrum was from the 8S7/2→6IJ transition of Gd3+.Under 393 nm excitation,the strongest emission at 591 nm was from the 5D0→7F1 magnetic dipole transition of Eu3+,maybe due to the distribution of some Eu3+ in the inverse symmetry sites.With the increasing of the sintered temperature,the fluorescent intensity increased,which might be the result of larger grain size with more excitated Eu3+ ions per unit volume.However,the fluorescence decay time at 591 nm decreased,which could be ascribed to trap capture to resonance transfer fluorescence of Eu3+ ions.更多还原