论文部分内容阅读
采用均相沉淀法制备了均匀球形的Gd2O3:Eu3+@Y2O3核壳结构纳米发光材料.XRD结果表明经过800℃焙烧后样品为立方晶系的Gd2O3,并且晶体发育良好,包覆Y2O3之后Gd2O3的衍射峰位置无明显变化,但随着包覆厚度的增加,出现了立方晶系Y2O3的衍射峰.FTIR谱图观测到了Gd—O,Y—O伸缩振动吸收峰,随着包覆厚度的减少吸收峰增强,认为当包覆层的厚度适当时,颗粒表面的悬空键(断键)变少,Gd(Eu,Y)—O键增多所致.SEM表明包覆前后样品为均匀分散的球形结构.XPS分析进一步证明了表面包覆上了Y2O3.荧光光谱表明:纳米Gd2O3:Eu3+表面包覆不同厚度的基质Y2O3后,均观测到Eu3+离子的特征红光发射,当包覆厚度R=4∶1时的发光强度比未包覆的Gd2O3:Eu3+增强,认为核-壳型样品降低了纳米Gd2O3:Eu3+的表面效应给发光强度带来的负面影响.
The homogeneous spherical Gd2O3: Eu3 + @ Y2O3 core-shell nanostructured luminescent materials were prepared by homogeneous precipitation method.The XRD results showed that after calcination at 800 ℃, the samples were cubic Gd2O3 and the crystal developed well. The diffraction of Gd2O3 after the coating of Y2O3 However, with the increase of coating thickness, the diffraction peaks of cubic Y2O3 were observed.FTIR spectra showed the absorption peaks of Gd-O and Y-O stretching vibration, which were absorbed as the coating thickness decreased The results show that when the thickness of the coating is suitable, the number of dangling bonds (broken bonds) on the surface of the particles decreases and Gd (Eu, Y) -O bonds increase, and the SEM shows that the samples before and after coating have uniformly dispersed spherical structures XPS analysis further confirmed that the surface was coated with Y2O3.The fluorescence spectra showed that the characteristic red emission of Eu3 + ions was observed after the surface of nano-Gd2O3: Eu3 + was coated with Y2O3 with different thickness, and when the coating thickness was R = 4: 1 was higher than that of uncoated Gd2O3: Eu3 +. It is considered that the core-shell type samples have the negative effect on the luminescence intensity due to the surface effect of nano-Gd2O3: Eu3 +.