Molecular dynamics simulations, experiments and a theoretical model were used to investigate disordering and amorphization processes in material which was irradiated with Si or Au ions. In the molecular dynamics simulations, large disordered domains which consisted of interstitials and antisite defects were created in the cascades which were produced by Au primary knock-on atoms. On the other hand, Si primary knock-on atoms generated only small interstitial clusters; with most of the defects being single interstitials and vacancies that were distributed over a large region. The data for cluster spectra which were obtained from molecular dynamics simulations were used to calculate the relative cross-sections for in-cascade amorphization (or clustering) and in-cascade defect-stimulated amorphization. The ratio of these cross-sections, for Si and Au, was in excellent agreement with those deduced from experimental data; when fitted using a direct-impact defect-stimulation model. It was suggested that the higher observed disordering rate and the residual disorder after annealing (300K) following implantation with Au2+ were associated with a higher probability for in-cascade amorphization or large disordered cluster formation. The observed difference in behavior of the accumulation and recovery of disorder in material which was implanted with Si+ and Au2+ was qualitatively consistent with the present molecular dynamics simulations and the direct-impact defect-stimulation model.
Primary Damage States Produced by Si and Au Recoils in SiC: a Molecular Dynamics and Experimental Investigation. F.Gao, W.J.Weber, W.Jiang: Physical Review B, 2001, 63, 214106 (6pp)