MCeO_3∶Eu^(3+)(M=Sr,Ba)的合成及发光性质研究

Synthesis and Spectral Properties of Eu^(3+)-Doped MCeO_3(M=Sr, Ba)

利用高温固相反应法合成了Eu3+掺杂的MCeO3(M=Sr,Ba)发光粉末样品,采用X射线衍射技术和荧光光谱等测试手段分别对其物相组成和发光性质进行了研究。X射线衍射结果显示,Eu3+离子容易替代MCeO3晶格中M2+离子的位置。荧光光谱测试结果表明,Eu3+掺杂的SrCeO3和BaCeO3样品在紫外波段存在着非常宽的吸收带,峰值分别位于311和320nm左右,它们属于Ce4+-O2-的电荷迁移带,SrCeO3和BaCeO3基质与Eu3+离子之间存在着能量转移。在MCeO3∶Eu3+样品中,Eu3+的发射主要来自于5D0激发态能级,其中以磁偶极跃迁5D0—7F1发射强度为最大;此外样品中还存在着较高的5D1激发态能级的辐射跃迁。SrCeO3∶Eu3+样品的发射强度远大于BaCeO3∶Eu3+样品。

Eu^3＋-doped MCeO3 （M= Sr, Ba） powder samples were prepared by a solid-state method, and their characteristics were investigated by the use of XRD and fluorescence spectra. The XRD results show that Eu^3＋ ions have a preference for M^2＋ over Ce^4＋ sites in MCeO3 （M=Sr, Ba） lattice. The excitation spectra of SrCeO3 ： Eu^3＋ and BaCeO3 ： Eu^3＋ display a much broad absorption band peaking at about 311 nm and 320 nm, respectively. This broad band is attributed to the charge transfer from O^2- to Ce^4＋ and the energy transfer from SrCeO3 and BaCeO3 to Eu^3＋. In the MCeO3 ： Eu^3＋ samples, the emission transitions of Eu^3＋ originating from ^5D1 and ^5D0 excited states can be observed, among which the ^5D0-^7F1 magnetic-dipole transition is the most intense emission. The emission of Eu^3＋ from the Eu^3＋ doped SrCeO3 lattice is much stronger than that of Eu^3＋ from the Eu^3＋ doped BaCeO3 lattice.