Ca_(1-x)Al_2Si_2O_8∶Eu_x表面结构与荧光强度相互关系的研究

Research on the Relationship between Surface Structure and Fluorescence Intensity of Ca_(1-x)Al_2Si_2O_8∶Eu_x

采用固相法分别在1 150,1 250,1 350,1 450℃下制备了Ca_(1-x)Al_2Si_2O_8∶Eu_x(x=0,0.01,0.05,0.15)系列微晶材料。通过X射线衍射仪(XRD)、拉曼光谱仪(Raman)、光致发光光谱仪(PL)和X射线荧光光谱仪(XRF)研究了CaAl_2Si_2O_8表面结构与荧光强度之间的相互关系。XRD和Raman结果表明:在制备CaAl_2Si_2O_8材料的过程中,随着温度不断升高,原材料逐渐结晶形成结构较为完整的CaAl_2Si_2O_8相;并且从拉曼光谱可以清晰看出,当Eu掺杂量相同时,随着烧结温度的升高,Si—O非晶相逐渐减少,硅氧四面体逐步形成,其振动峰位置逐渐向低波数移动,但当温度过高时硅氧四面体破坏形成宽化的的非晶峰;Eu的掺杂阻碍了Al取代Si位置的过程,因此在1 620波数处振动峰先增强后减弱。这种材料表面结构的变化与Eu的掺杂密切相关,影响着材料表面Eu原子数量分布。PL和XRF结果表明:相同Eu掺杂量时,温度越高越有利于Eu原子扩散到样品表面,从而使样品的荧光强度更强。因此样品的荧光强度和样品单位表面积Eu原子数量存在正比关系。

Ca_（1-x）Al_2Si_2O_8∶Eu_x（x=0,0.01,0.05,0.15）were synthesized by solid-state reaction respectively at 1 150,1 2501 350 and 1 450 ℃.With X-ray diffraction（XRD）,Raman spectroscopy（Raman）,photoluminescence spectroscopy（PL）and Xray fluorescence spectrometer（XRF）,the relationship between surface structure and fluorescence intensity of Ca_（1-x）Al_2Si_2O_8∶Eu_x were studied.XRD and Raman results show that,CaAl_2Si_2O_8 anorthite single-phase has formed gradually along with the temperature rising in the process of synthesis.Raman spectroscopy is clear that when the Eu doping amount is the same,Si—O amorphous phase disappear gradually and the CaAl_2Si_2O_8 phase form gradually with the temperature increases.As the temperature increases,vibration peaks position silicon oxygen tetrahedron shift to lower wave number.When 1 450℃,the temperature is too high to destroy the structure of silicon oxygen tetrahedron.At the same time,there is a broadening amorphous peak appears in Raman spectroscopy.The procedure of Al to replace Si is hindered with Eu doped in.It is the result that the peak at1 620cm^-1 decreases after the first increases.The change of surface structure associated with the scattering amount of Eu.PL and XRF results show that：as the temperature increases,the amount of Eu atom scattering on the material surface increases gradually,this change lead to the fluorescence intensity raise.Therefore,there is proportional relationship between the fluorescence intensity of the samples and the number of samples per unit surface area of Eu atoms.