PNNL

Abstract

The integration of experimental and computer simulation studies is providing atomic-level understanding of the radiation-damage processes in silicon carbide (SiC) that result in the creation of point defects, defect clusters and long-range structural disorder. Ab initio calculations are used to determine the energetics of defect formation. Molecular dynamics methods have been used to study both the energy dependence of defect production and the effects of cascade overlap processes. The temperature dependence of radiation damage has been investigated for a wide range of ion species, and the accumulation and recovery of damage on both the Si and C sublattices have been determined. The experimental and molecular dynamics results for damage accumulation are in good agreement; thus, providing an atomic-level interpretation experimentally observed features. Multi-axial channeling measurements along three axes indicate that Si and C interstitials are well-aligned along the axis, consistent with ab initio results.