Effects of Annealing Temperature and SiO2 Matrix on the Structure and Optical Properties of Co-Doped ZnAl2O4/SiO2 Nanoglass-Ceramic Composites
Effects of Annealing Temperature and SiO2 Matrix on the Structure and Optical Properties of Co-Doped ZnAl2O4/SiO2 Nanoglass-Ceramic Composites
复制标题
退火温度和SiO2基体对共掺杂ZnAl2O4/SiO2纳米玻璃陶瓷复合材料结构和光学性能的影响
DOI：
10.1021/jp209837q
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发表时间：
2012-01-26
影响因子：
3.7
通讯作者：
Yuan, Duorong
中科院分区：
文献类型：
--
作者：
Duan, Xiulan;Wang, Xinqiang;Yuan, Duorong
含尖晶石纳米晶的钴掺杂微晶玻璃作为光学材料受到了广泛的关注。材料的组成和制备条件将影响其结构和光学性能。本文采用溶胶-凝胶法制备了（100-x）Co0.1Zn0.9Al2O4-xSiO（2）（x = 0-95）样品，并用X射线粉末衍射和透射电子显微镜对样品进行了表征。X射线光电子能谱和Al-27固体核磁共振谱被用来研究作为退火温度和SiO2浓度的函数的纳米复合材料中的阳离子和氧的化学环境。结果表明，所制备的样品均由SiO2基体和包裹的ZnAl 2 O 4纳米晶颗粒组成。除了在Co0.1Zn0.9Al2O4纳米晶体中存在的四面体、八面体和第二八面体配位位外，在纳米复合材料中还观察到Al 3+离子的五配位。反转参数（Al ~（3+）离子在四面体位置的分数的两倍）随着SiO_2浓度和退火温度的降低而增大。吸收光谱表明，Co2+离子位于四面体网站，以及在八面体网站的纳米复合材料。随着退火温度的升高和SiO2浓度的增加，八面体Co ~（2+）离子的吸收峰强度逐渐减弱。
Co-doped glass ceramics containing spinel nanocrystals attach much attention as optical materials. The composition and preparation conditions of the material will influence its structure and optical properties. In this study, the samples (100-x)Co0.1Zn0.9Al2O4-xSiO(2) (x = 0-95) were prepared by the sol-gel method and characterized by X-ray powder diffraction and transmission electron microscopy. X-ray photoelectron spectroscopy and Al-27 solid-state NMR spectroscopy were used to study the chemical environments of cations and oxygen in the nanocomposites as a function of annealing temperature and SiO2 concentration. The results show that all the samples are composed of a silica matrix and enclosed ZnAl2O4 nanocrystalline particles. Besides the tetrahedral, octahedral, and second octahedral coordination sites present in Co0.1Zn0.9Al2O4 nanocrystals, the five-coordinate sites of Al3+ ions are observed in the nanocomposites. The inversion parameter (two times the fraction of Al3+ ions in the tetrahedral sites) increases with the decrease of SiO2 concentration and annealing temperature. The absorption spectra indicate that Co2+ ions are located in the tetrahedral sites as well as in the octahedral sites in the nanocomposites. The intensity of the absorption peak corresponding to octahedral Co2+ ions decreases with the increase of annealing temperature and SiO2 concentration.