Fluorine-intercalated carbon fibers III. A transmission electron microscopy study

A high resolution transmission electron microscopy study of fluorine-intercalated carbon fibers has been carried out on two types of host materials: high-temperature treated pitch-based and PAN-based fibers. TEM images and corresponding Fourier transforms have shown that only stage-1 compounds and graphitic-type domains are detected in the experiment conditions. In particular, no interlayer spacing corresponding to higher staged materials have been noticed. The observed results can be correlated to the ratio of semi-ionic to covalent FC bonding previously determined by XPS. The disorder mostly depends on the nature of the host fiber and on the amount of mobile species that may react with the graphene layers during the deintercalation process, which is favored by the high-vacuum conditions.