Modelling irradiation induced glass transition in thin films

By the interface migration-charge transfer (IMCT) atomistic model the nucleation of amorphous or crystalline phases is modelled in binary compound films, both metallic and non-metallic, where dense collision cascades form upon irradiation. Non-equilibrium compositional and electronic density profiles develop at the interface between each cascade and the surrounding crystalline matrix due to interface enrichment of one of the film constituents. By local charge transfer reactions (CTR), system relaxation is mimicked via formation of dimers of an effective compound. We calculate the energy cost to produce one such dimer, the difference of formation enthalpy between each effective compound and the corresponding initial compound and the local strain associated to a CTR for representative sets of metallic and non-metallic ion bombarded compounds. Qualitative differences are found in the parameter trends between the two groups of compounds amorphized and respectively, crystalline under ion beam irradiation.