  We report a statistical analysis of sizes and compositions of clusters
produced in cascades during irradiation of SiC. The results are obtained using
molecular dynamics (MD) simulations of cascades caused by primary knock-on
atoms (PKAs) with energies between 10 eV and 50 keV. The results are averaged
over six crystallographic directions of the PKA and integrated over PKA energy
spectrum derived from the Stopping and Range of Ions in Matter (SRIM) code.
Specific results are presented for 1 MeV Kr ion as an example of an impinging
particle. We find that distributions of cluster size n for both vacancies and
interstitials obey a power law f = An^(-S) and these clusters are dominated by
carbons defects. The fitted values of A and S are different than values
reported for metals, which can be explained through different defect energetics
and cascade morphology between the two classes of materials. In SiC, the
average carbon ratio for interstitial clusters is 91.5%, which is higher than
the ratio of C in vacancy clusters, which is 85.3%. Size and composition
distribution of in-cascade clusters provide a critical input for long-term
defect evolution models.
