稀土掺杂氟化镁钾纳米晶的合成及其光谱特性

采用微乳液法合成了Eu²⁺,Ce³⁺单掺和双掺KMgF₃纳米晶,分析了样品的结构与形态. 结果表明,所合成的样品均为单相,颗粒粒度分布均匀. 讨论了光谱特性并与高温固相法合成的产物作了对比. 研究发现,在KMgF₃纳米晶双掺体系中,由于Eu²⁺和Ce³⁺竞争吸收激发能,只能观察到Ce³⁺的发射带; 而在KMgF3多晶共掺体系中,因为存在Ce³⁺→Eu²⁺能量传递过程,只能观察到Eu²⁺的发射峰.

Synthesis and Spectral Properties of Eu2+/Ce3+ Doped Potassium Magnesium Fluoride Nanoparticles

Phosphors of KMgF3∶Eu2+, KMgF3∶Ce3+and KMgF3∶Eu2+,Ce3+nanoparticles were synthesized in cetyltrimethylammonium bromide(CTAB)/2-octanol/water microemulsion systems. X-ray diffraction(XRD) patterns was used to identify the formation of KMgF3 phase without detectable impurity. Environment scanning electron microscopy(ESEM) images show the even size distribution of the nanoparticles with pellet morphology. Photoluminescence characteristics of the rare earth ions doped nanoparticles were investigated and compared with that of the polycrystalline products prepared by solid state reaction at a high temperature. The emission band of the Ce3+ could only be observed due to absorbing the exciting energy competitively between the Eu2+ and Ce3+ in co-doped system of KMgF3 nanoparticles,while the emission peak of the Eu2+could only be observed due to energy transfer from Ce3+ to Eu2+appearing in the KMgF3∶Eu2+,Ce3+polycrystalline powder. The mechanism on energr transfer from Ce3+ to Eu2+ in polycrystal and from Eu2+ to Ce3+in nanocrystal KMgF3∶Eu2+,Ce3+was discussed by means of Eu2+ excitation spectrum and Ce3+emission spectrum.