A methodology to optimize the quantification of sp(2) carbon fraction from K edge EELS spectra

作者：Bernier N^*; Bocquet F; Allouche A; Saikaly W; Brosset C; Thibault J; Charai A

来源：Journal of Electron Spectroscopy and Related Phenomena, 2008, 164(1-3): 34-43.

DOI：10.1016/j.elspec.2008.04.006

• graphite
• amorphous carbon
• electron energy loss spectroscopy
• electronic structure
• bonding

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.

• 出版日期2008-7
• 单位中国地震局