A methodology to optimize the quantification of sp2 carbon fraction from K edge EELS spectra
A methodology to optimize the quantification of sp2 carbon fraction from K edge EELS spectra
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DOI：
10.1016/j.elspec.2008.04.006
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发表时间：
2008-07-01
影响因子：
1.9
通讯作者：
Charai, A.
中科院分区：
文献类型：
--
作者：
Bernier, N.;Bocquet, F.;Charai, A.
提出了一种选择一致方法的方法，利用电子能量损失谱（EELS）提取碳质材料中sp(2)键合碳原子的分数。根据这种方法，一个可靠的方法必须同时满足两个标准。第一个步骤是在一个完美的石墨样品上验证R = I(pi*)/(I(pi*)+I(sigma*))-比率的实验演化与作为实验设置函数的理论预测是完全一致的。第二个准则是测量无定形碳样品中的sp(2)组分，其波动最小。我们测试了三种常用的r提取技术，并展示了它们出现的一些故障。因此，我们实现了一个更精确的r提取过程，该过程可以解释预测的石墨r演化，并显示出低的内在4%噪声，这是由sp(2)分数波动确定的。此外，我们还检查了我们的方法在不同实验分辨率下对具有不同sp(2)含量的样品获得的EELS光谱的可转移性。(C) 2008 Elsevier B.V.版权所有
A methodology is presented to select a consistent method, using electron energy loss spectroscopy (EELS), to extract the fraction of sp(2)-bonded carbon atoms in carbonaceous materials. According to this methodology, a reliable method has to conjointly fulfill two criteria. The first one consists in verifying, on a perfect graphite sample, that the experimental evolution of R = I(pi*)/(I(pi*)+I(sigma*))-ratios is in good agreement with the one theoretically predicted as a function of experimental settings. The second criterion consists in measuring sp(2) fractions in amorphous carbon samples with a minimum of fluctuation. We test three commonly used R-extraction techniques, and we show that they exhibit some failures. We thus implement a more accurate R-extraction process that accounts for the predicted graphite R-evolution and exhibits a low intrinsic 4%-noise, as determined from the sp(2) fraction fluctuation. Moreover, we check the transferability of our method on a wide range of EELS spectra, acquired with different experimental resolutions on samples exhibiting various sp(2) contents. (C) 2008 Elsevier B.V. All rights reserved.