Modelling of nanocrystalline insulators response to swift heavy ion irradiation

Abstract

We apply a hybrid multiscale model to describe structural damage in nanocrystalline insulators irradiated with swift heavy ions. The approach couples Monte Carlo code TREKIS tracing excitation of the electron ensemble and energy transfer to target atoms with the molecular dynamics simulating the lattice kinetics during its relaxation. We compare response of amorphizable and non-amorphizable nanocrystalline targets to strong perturbations initiated by an ion impact. The recrystallization processes observed in non-amorphizable MgO and Al2O3 strongly affects the grain boundaries that may result in association and enlargement of nanoparticles. Strong material heating and expansion in the track core can form voids near the grain boundaries. In contrast, swift heavy ion passage in the amorphizable sample almost do not affect the grains morphology forming amorphous tracks, similarly to the damage in the bulk.