INTERSTITIAL STRING MODEL FOR DEFECTIVE GRAPHITES

The carbon atoms in defective graphites are arranged mainly in layers, with a spacing that is sample dependent and larger than that in high-perfection graphites. The generally accepted explanation for this variation is that the larger separations in more disordered graphite arise from poorer mutual orientation of the graphite layers ("turbostratic disorder"). Computer models of interstitials in supercells show that strings of interstitials along the hexagonal axis are unusually stable and might better explain the spacings observed and other properties, certainly for neutron-irradiated graphite, but possibly also for other graphites.