摘要
采用两步水解的溶胶凝胶和气体反应工艺，制备了ＺｎＳ·ＳｉＯ２纳米复合材料。ＺｎＳ微晶的尺寸为２～６ｎｍ，具有立方结构。其电子衍射具有稀疏的斑点和较少的衍射环。通过吸收光谱和荧光光谱观察到蓝移现象。采用简并四波混频方法得到复合材料的三阶非线性光学系数为２．８×１０－２０ｍ２·Ｖ－２，考虑ＺｎＳ的浓度影响后为２．８×１０－１７ｍ２·Ｖ－２。径向分析函数和Ｒａｍａｎ光谱表明，纳米复合材料中的Ｓｉ—Ｏ网络单元小于熔融玻璃中的网络单元，Ｓｉ—Ｓｉ（Ｉ）键键长增大，并存在着除架状网络以外的层状、链状网络。这些结构影响了材料的非线性光学性能。纳米微晶的形成可能是由于玻璃相网络中的Ｚｎ２＋离子扩散到气孔边缘处与Ｓ２－离子反应的结果。
ZnS·SiO 2 nanocomposites were prepared through two step sol gel and gas reaction process.The crystallite size is from 2 to 6 nm with a cubic structure observed by XRD.The scattered diffraction pattern and smaller rings were shown in the electronic diffraction analysis through TEM.The quantum size effect(blue shift)was observed in absorption spectra and photoluminescence spectra of ZnS·SiO 2 with different reaction time between ZnO·SiO 2 and H 2S gas.Degenerate four wave mixing(DFWM)method was used to determine the 3rd order nonlinear optical susceptibility χ (3) ,the value is 2 8×10 -20 m 2·V -2 ,which becomes 2 8×10 -17 m 2·V -2 ,if considering the influence of concentration of ZnS crystallites in the nanocomposites.The results of radial distribution function(RDF)and Raman spectra indicate that the network cell of Si—O structure in ZnS·SiO 2 is smaller than that in glass prepared by melting process;and Si—Si(I)bond is enlarged;and shell shaped and chain shaped structures exist except the frame shaped structure.These bond brokened structures affect the density,the refractive index and the nonlinear optical susceptibility of the material.Based on above experiments,the formation of ZnS crystallites in nanocomposites is regarded to be resulted from the diffusion of Zn 2+ from network in glass phase and the reaction with H 2S gas at the edges of pores.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
1997年第3期274-280,共7页
Journal of The Chinese Ceramic Society
基金
西安交通大学精细复合功能材料实验室开放资助
关键词
复合材料
氧化硅
硫化锌
半导体材料
纳米材料
nanocomposite,radial distribution function,Raman spectrum,quantum size effect,nonlinear optical effect
