Advanced Spectroscopic Analyses on a:C-H Materials: Revisiting the EELS Characterization and its Coupling with Multi-Wavelength Raman Spectroscopy

摘要

Hydrogenated amorphous carbons (a:C-H) are very promising materials for numerous applications including coatings of data storage devices due to the long-term stability of their properties. In order to improve their performances, a full understanding of their local chemistry is highly required. Fifteen years ago, according to the seminal work of Ferrari et al. , electron energy loss spectroscopy (EELS) was the most used technique to get such kind of quantitative information on these materials. Nowadays the complexity of the physics phenomena behind the EELS spectroscopy is well known and this technique is regarded as time-consuming and difficult to interpret properly. Other optical techniques such as Raman spectroscopy are now clearly favored by the scientific community. However not only they lack of the spatial resolution, which can be obtained by EELS developed in a scanning transmission electron microscope (STEM), but also their interpretations is subject to discussion.