A study was made of the atomic-scale mechanisms of radiation damage recovery, by molecular dynamics simulations of irradiation cascades in a β-SiC model system, containing one general (001) twist grain boundary in the direction approximately perpendicular to the cascade. The (001) grain boundary has a disordered atomic structure, representative of high-angle, high-energy boundaries in cubic SiC . Compared to the perfect crystal model system, a relevant effect of grain boundaries on the annealing of cascade defects was found; both in terms of localization of defects, which were preferentially concentrated around the grain boundary, and of relative defect recovery efficiency. In general, C interstitials were the prevalent type of defect over the whole range of energies explored. A slight grain boundary expansion was observed, accompanied by a broadening of the central atomic planes.

Point-Defect Recombination Efficiency at Grain Boundaries in Irradiated SiC. A.Moriani, F.Cleri: Physical Review B, 2006, 73[21], 214113 (9pp)