Structure and stability of irradiation-induced Frenkel pairs in 3C-SiC using first principles calculations

We have performed first principles calculations of intrinsic point defects and Frenkel pairs in cubic silicon carbide, using generalized gradient approximation. The considered Frenkel pairs have been obtained from a previous work on the determination of threshold displacement energies [G. Lucas, L. Pizzagalli, Phys. Rev. B 72 (2005) 161202]. Structures and formation energies of the defects are described. We found that our GGA results are in very good agreement with previous LDA studies. We found that Frenkel pairs are more stable than isolated single defects, especially for silicon interstitials, pointing to an attractive interaction between vacancies and interstitials as expected. (c) 2006 Elsevier B.V. All rights reserved.