PNNL

Abstract

Atomic-level simulations are used to determine defect production, cascade-overlap effects, and defect migration energies in SiC. Energetic C and Si collision cascades primarily produce single interstitials, mono-vacancies, antisite defects, and small defect clusters, while amorphous clusters are produced within 25% of Au cascades. Cascade overlap results in defect stimulated cluster growth that produces amorphization. The good agreement of disordering behavior and changes in volume and elastic modulus obtained computationally and experimentally provides atomic-level interpretation of experimentally observed features. Simulations indicate that close-pair recombination activation energies range from 0.24 to 0.38 eV, and long-range migration energies for interstitials and vacancies have been determined.