A program using two-dimensional dislocation dynamics with anisotropic strain equations has been written to simulate the dimensional change and stored elastic energy of irradiated graphite. A dislocation based model is put forward as a vehicle for both the longstanding atomic displacement model for dimensional change in irradiated graphite and a new model based on basal slip.
As expected the introduction of prismatic dislocation loops (climb dipoles in 2D) results in the expansion of the graphite crystal in the c-axis direction. Interestingly the stored elastic energy of the system was found to increase with number of dislocation dipoles and reached a maximum at the density which Burakovsky et al. (Phys. Rev. B 61, 15011–15018 (2000) ) predicted for melting. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)