The structure of mesophase carbon powders prepared by heating coal-tar pitch at different temperatures was studied using the small-angle X-ray scattering method. The wide-angle diffraction profiles of mesophase carbon powders indicate only the first peak at q = 18 nm-1 and subsequent broad oscillations. A single graphite layer is suggested to be one of the local structural orderings in the present mesophase carbon powders similar to those of carbon black and amorphous carbon. The small-angle X-ray scattering data clearly suggest that mesophase carbon powders include structural inhomogeneity, and size is relatively small on the order of 10 nm in gyration radius. A fraction of small size inhomogeneity increases according to change in heating temperature (i.e., C/H ratio). The Porod plot of the scattering intensity also suggests that some significant structural change is induced by graphitization in mesophase carbon powders at the early stage of heating.
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Physical and Theoretical Chemistry