Physical ageing in vitreous As13.5Ge4.5Se82 modified by high-energy gamma-irradiation

Influence of high-energy Co60 gamma-irradiation on natural physical ageing in vitreous As13.5Ge4.5Se82 is studied. It is shown that slow relaxation processes that occur in this material after 10 yr of natural storage can be significantly affected by irradiation. The increase in glass transition temperature and endothermic peak area in the vicinity of glass transition is recorded after gamma-irradiation and during an additional 1 yr period of natural storage of the irradiated glasses. It is associated with gamma-activated relaxation of As13.5Ge4.5Se82 glass network towards a new thermodynamic state, which is closer to thermodynamic equilibrium of super-cooled liquid. The process occurred under stationary radiation field conditions is considered as pure γ-induced physical ageing, and those observed after radiation treatment-as post-radiation physical ageing.