Role of pre-existing point defects on primary damage production and amorphization in silicon carbide (beta-SiC)

DR Sahoo and I Szlufarska and D Morgan and N Swaminathan, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS, 414, 45-60 (2018).

DOI: 10.1016/j.nimb.2017.10.011

Molecular dynamics simulations of displacement cascades were conducted to study the effect of point defects on the primary damage production in beta-SiC. Although all types of point defects and Frenkel pairs were considered, Si interstitials and Si Frenkel pairs were unstable and hence excluded from the cascade studies. Si (C) vacancies had the maximum influence, enhancing C (Si) antisites and suppressing C interstitial production, when compared to the sample without any defects. The intracascade recombination mechanisms, in the presence of preexisting defects, is explored by examining the evolution of point defects during the cascade. To ascertain the role of the unstable Si defects on amorphization, simulations involving explicit displacements of Si atoms were conducted. The dose to amorphization with only Si displacements was much lower than what was observed with only C displacements. The release of elastic energy accumulated due to Si defects, is found to be the amorphizing mechanism.

Return to Publications page