Dynamic Simulation of Interstitial Atom in Graphite

Abstract

The formation of an interstitial atom in graphite crystals is simulated by the molecular dynamic method, in which the characteristic point is that the effect of covalent bonds in hexagonal lattices is taken into account as the non-central force interaction. It is found that the interstitial atom rests at an asymmetric site in the hexagonal lattice, which is deviated from the symmetric site obtained in the elastic membranes model for the lamellar structure of graphites. This dynamic process is analyzed in detail. The self-energy and the migration energy of an interstitial atom are obtained as 1.28 eV and 0.01 eV, respectively. The increase of crystal volume due to an interstitial atom amounts to 3.32 atomic volume, which coincides with the experimental value fairly well.