The surface energies of graphite

A discussion is presented describing the possible influence of the internal surface energy of polycrystalline and pyrolytic graphites on three phenomena: (a) the thermodynamic “standard” state of carbon, (b) the graphitization process, and (c) the structural stability of graphites at high temperatures. In order to do this, the surface enthalpies and free energies of the basal surface and edge faces have been calculated from a number of sources, and their temperature dependence up to 3000K discussed. Suggestions have been made for methods to measure both basal surface and “edge” surface energies more directly.