Y_2SiO_5:Eu~(3+)纳米荧光粉的光谱特性研究

用凝胶燃烧法制备Y2SiO5:Eu3+纳米荧光粉.X射线衍射实验发现,在1 100℃以下烧结得到X1型物相,属单斜晶系,空间群为P21/c;在1 300℃以上烧结得到X2型物相,属单斜晶系,空间群为C2/c.研究了各样品的红外光谱,发现同物相的校正面积和校正高度随颗粒增大而增大,在物相转型时发生突变,X2型吸收峰位发生蓝移;研究了室温下样品在395 nm紫外光激发下得到的发射光谱,发现纳米荧光粉的5D0→7F0峰相比体材料发生蓝移,5D0→7F2峰相比于体材料中心位置变化不大,而谱带明显加宽.随着烧结温度降低,荧光粉颗粒减小,5D0→7F2的跃迁峰强度回落,但5D0→7F1与5D0→7F4的跃迁峰强度变化不大.Eu3+在Y2SiO5基质中占有两个不同的格位,不同的能级产生两套光谱致使峰数比退简并的峰数多.

Study on the spectra of an nanocrystalline Y2SiO5:Eu3+ prepared by the glycine combustion synthesis

Nanocrystalline Y_2SiO_5: Eu~(3+) fluorescence powder is prepared by the combustion synthesis assisted by the glycine.It is discovered on the basis of XRD research that samples to calcinate at lower temperatures than 1 100 ℃ belong to an X_1 type which is the monoclinic crystal and its space group is P2_1/c.But samples to calcinate at higher temperatures than 1 300 ℃ belong to an X_2 type which is also monoclinic crystal and its space group is C_2/c.The infrared spectra of the samples have been studied.The result shows that correction height and correction area increase with the size of the particle in the same crystal type.They are mutated when the crystal type is changed.The absorption peak of Y(Eu)―O in X_2 type appears blue shift.The emission spectra of samples excited by the radiation at 395 nm at the room temperature have been studied.It is found out that occurs blue shift in the peak corresponding to ~5D_0→~7F_0 for the nanocrystallite compared to a body material,and the transition of the peak center of the emission corresponding to ~5D_0→~7F_2 shifts little compared with the same body material,but the width of the emission peak is obviously widened.The grain of fluorescent powder monishes and the intensity of the transition ~5D_0→~7F_2 decreases with the calcining temperature.But the intensities of the transitions ~5D_0→~7F_1 and ~5D_0→~7F_4 change little.Eu~(3+) ions occupy two different locations in Y_2SiO_5 host lattice,which possesses different energy levels.The spectrum peaks that two series of the spectrum bring are gigger than that is caused from the degeneration.