空气条件下合成的CaBPO_5:Eu、SrB_4O_7:Eu和Ba_3(PO_4)_2:Eu的XANES和发光性质

XANES and luminescence of CaBPO_5:Eu, SrB_4O_7:Eu and Ba_3(PO_4)_2:Eu prepared in air

测定了采用高温固相反应在空气条件下合成的发光体CaBPO_5:Eu、SrB_4O_7:Eu和Ba_3(PO_4)_2:Eu的Eu-L_3边的X射线吸收近边结构(XANS)谱和发光光谱。从发光体的Eu-L_3边XANES可见,Eu^(3+)-L_3边能量比Eu^(2+)-L_3边能量高7—8eV;3个发光体的激发光谱和发射光谱均可看到Eu^(2+)的4f-5d跃迁和Eu^(3+)的4f-4f跃迁。发光体的Eu-L_3边的XANES和发光光谱说明空气条件下合成的发光体中Eu^(3+)可部分还原为Eu^(2+)。

The Eu-L3 edge XANES and luminescent spectra of CaBPO5:Eu, SrB4O7:Eu and Ba3(PO4)2:Eu prepared by solid state reaction at high temperature in air were determined. It can be observed from the Eu-L3 edge XANES spectra that energy of Eu3+-L3 edge is 7-8 eV higher than that of Eu2+-L3 edge in the luminescent materials. The 4f-5d transition of Eu2+ and the 4f-4f transition of Eu3+ can be found simultaneously in the excitation and emission spectra of these materials, respectively. The results of Eu-L3 edge XANES and luminescent spectra imply that Eu3+ can be partially reduced to Eu2+ in these materials when they were prepared in air atmosphere.