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首页> 外文期刊>Journal of Alloys and Compounds: An Interdisciplinary Journal of Materials Science and Solid-state Chemistry and Physics >Rare earth doped sol-gel materials as potential absorbance standards
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Rare earth doped sol-gel materials as potential absorbance standards

机译：稀土掺杂溶胶-凝胶材料作为潜在的吸收标准

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摘要

Our studies are aimed towards the preparation ofabsorbance materials for use in the UV and combined UV-VISregions using sol-gel derived silica as the matrix. Our currentresearch is directed towards understanding the extent of molecularinteractions between the dopant phase (in this case metal salts) andthe gel matrix and the effect of these interactions on thespectroscopic signature of all components in the gel-glasscomposite. The addition of cerium(III) to the sol-gel reagentsaffected the rate of drying of the gel-silicas suggesting a directinteraction between the gel matrix and the metal ions themselves.Confirmatory evidence was provided by low temperature ~(29)Sisolution NMR measurements during the early stages of gelformation where Q_0 and Q1_ species disappeared from thereaction medium more quickly in the presence of the dopant. TheUV-VIS spectrum of dried sol-gel glasses containing Ce(III)showed that the as-prepared material contained principally theaqua-ion with nine-fold coordination. Evacuation of the ceriumdoped glass gave a spectrum commensurate with the metal ionhaving a lower coordination number and after heating the Ce(III)spectral response was no longer observed. It is suggested thatoxidation of Ce(III) to Ce(IV) occurred during thermal treatment.When gel glasses were prepared with both cerium(III) andneodymium(III) the signal arising from the presence of the ceriumions was diminished. Moreover, after evacuation of the glasses andheat treatment (800 deg C), the Ce(III) spectrum could no longer be observed.
机译：我们的研究旨在以溶胶-凝胶衍生的二氧化硅为基质，制备用于紫外和紫外-可见光组合区域的吸光材料。我们目前的研究旨在了解掺杂剂相（在这种情况下为金属盐）与凝胶基质之间的分子相互作用的程度，以及这些相互作用对凝胶-玻璃复合物中所有组分的光谱特征的影响。溶胶-凝胶试剂中添加铈（III）会影响凝胶硅胶的干燥速度，表明凝胶基质与金属离子本身之间存在直接相互作用。低温〜（29）Sisolution NMR测量提供了确证在掺杂剂存在的情况下，Q_0和Q1_物种从反应介质中消失的速度更快。含有Ce（III）的干燥溶胶-凝胶玻璃的UV-VIS光谱表明，制得的材料主要含有九倍配位的水族离子。抽空铈掺杂的玻璃给出的光谱与金属离子具有较低的配位数，并且在加热后不再观察到Ce（III）光谱响应。这表明在热处理过程中会发生Ce（III）氧化为Ce（IV）。当同时使用铈（III）和钕（III）制备凝胶玻璃时，由铈离子的存在引起的信号会减少。此外，在抽空眼镜并进行热处理（800摄氏度）后，不再能观察到Ce（III）光谱。

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