Infrared spectra and luminescence properties of (Yx,Gd0.95–x)BO3:Eu0.053+

The luminescence compound (Yx,Gd0.95–x)BO3:Eu0.053+ with a single phase hexagonal crystal structure has been synthesized by the solid state reaction. The c/a value is linearly decreasing when the ratio of Y3+/Gd3+ is increasing, which indicates that the solid-solution of YBO3 and GdBO3 is forming. The two symmetric stretching vibration peaks of the BO4 anion at 866 and 912 cm−1 in the FTIR spectrum exist in two forms in the solid solutions. The local symmetric environment surrounding the Eu3+ ion was lowered with the decrease of Y3+/Gd3+ ratio. The host absorption band and Eu3+–O2− charge transfer band were observed in the excitation spectra of (Yx,Gd0.95−x)BO3:Eu0.053+. In particular, the relative intensity of Eu3+–O2− charge transfer band sharply decreased when the ratio of Y3+/Gd3+ increased was identified by the variation of local symmetric environment around Eu3+. The ratio of the fluorescence intensity of 5D0 → 7F2 transition and 5D0 → 7F1 transition (R/O ratio) is decreasing with the increasing of Y3+ content.