Imaging of defects and recrystallization studies in ion implanted graphite.

This work reports the study of ion-implantation induced damage and annealing in the highly anisotropic semimetal graphite using high resolution transmission electron microscopy. The recrystallization process and regrowth kinetic are compared for highly oriented pyrolytic graphite (HOPG) and benzene derived graphite fibers as host materials. We obtain activation energies of ~ 0.7 eV/atom for grain growth processes along both the c-axis and in the graphite basal plane for the fiber host. Post-ion implantation annealing of HOPG shows two competing processes; epitaxial regrowth and regrowth with random orientation of the crystallites. For both host materials time dependence of ~ t1/2 and t1/4 are obtained for the regrowth kinetics in the basal plane and along the c-axis, respectively. The regrowth process is explained by the annealing of dislocations.