Si displacement cascades revealed by atomic-scale simulations in 3C-SiC

The primary damage by displacement cascades in 3C-SiC at 300 K has been stu died by molecular dynamics (MD). A large number of cascades, with energies from 0.2 to 50 keV, have been simulated in order to investigate the effects of energy in defect production and clustering. The surviving defects are d ominated by C interstitials and vacancies. The number of Frenkel pairs incr eases with increasing cascade energy, but the efficiency of their productio n declines with increasing energy in a similar fashion to that found in met als. Although the number of antisite defects is smaller than that of Frenke l pairs, their production also increases with increasing cascade energy. Mo st surviving defects are single interstitials and vacancies, and the tenden cy of interstitials to form clusters is very week. The size of the intersti tial clusters is very small, which shows significantly different behavior t han obtained by MD simulations in metals. The current results provide the s tatistics of the primary damage states in SiC as a function of primary knoc k-on energy, which are important in upscaling these results to model behavi or over longer time and length scales.