Effect of structural disorder induced by external irradiation with heavy ions on the alteration of a four oxide borosilicate glass

The irradiation of glass by heavy ions induces structural damage, generally leading to a decrease in its chemical durability whose amplitude strongly depends on the glass chemical composition. Here, we investigate the effects of irradiation by 7 MeV Au ions (simulating the main ballistic effects induced by self-irradiation in nuclear glass) on the behavior of a 4-oxide borosilicate glass in both the initial and residual dissolution regimes. The comparison between irradiated and non-irradiated glasses provides insights into the predominant atomic mechanisms governing glass alteration processes. The most pronounced effect is observed on interdiffusion in acidic conditions, with the rate increased by more than an order of magnitude for the irradiated glass. We show that both the interdiffusion regime and the residual regime are controlled by the hydrolysis of the B-O-Si linkages, whereas under initial dissolution rate regime in basic conditions the rate-limiting step becomes the hydrolysis of Si-O-Si linkages. Overall, the observations suggest structural disorder due to external irradiation by Au ions primarily affects the kinetics of glass alteration without changing the fundamental nature of the limiting reactions.

Stéphane Gin, Mélanie Taron, Hélène Arena, Jean-Marc Delaye