Molecular dynamics simulation of defect production in irradiated beta-SiC

We used the molecular dynamics (MD) code MDCASK, in which the Tersoff poten tial is implemented, to study the mechanisms of defect production due to Si - and C-recoils of different energies in beta -SiC. In this gaper, we highl ight some of our most significant results to date. The threshold displaceme nt energies (TDEs) for Si- and C-atoms have been accurately determined alon g four main crystallographic directions. The difficulty of defining a singl e TDE in this material, also because of the effect of temperature, is discu ssed. High-energy (various keV) recoil-induced displacement cascades have b een simulated and it was found that defects on the C-sublattice always outn umber defects on the Si-sublattice, temperature scarcely affecting the numb er of Frenkel pairs produced within the cascade, Finally, our MD model seem s to have proved satisfactory in reproducing the experimentally observed pr ocess of irradiation-induced amorphization of SiC at cryogenic temperature. (C) 2000 Elsevier Science B.V. All rights reserved.