Comparison of radiation and quenching rate effects on the structure of a sodium borosilicate glass

The effects of quenching rate and irradiation on the structure of a sodium borosilicate glass were compared using ²⁹Si, ¹¹B, and ²³Na nuclear magnetic resonance and Raman spectroscopy. Quenching rate ranging from 0.1 to 3 * 10⁴ K min^-1 was studied. Various irradiation conditions were performed, i.e. gold-ion irradiation in a multi-energy mode (from 1 to 6.75 MeV), and Kr and Xe ion irradiations with energy of 74 and 92 MeV, respectively. In pile irradiation with thermal neutron flux was performed as well, to study the effect of alpha radiation from the nuclear reaction ¹⁰B(n,α)⁷Li. Both irradiation and high quenching rate induce similar local order modification of the glass structure, mainly a decrease of the mean boron coordination and an increase of Q³ units. Nevertheless, the variations observed under irradiation are more pronounced than the ones induced by the quenching rate. Moreover, some important modifications of the glass medium range order, i.e. the emergence of the D2 band associated to three members silica rings and a modification of the Si-O-Si angle distribution were only noticed after irradiation. These results suggest that the irradiated structure is certainly not exactly the one obtained by a rapidly quenched equilibrated melt, but rather a more disordered structure that was weakly relaxed during the very rapid quenching phase following the energy deposition step. Raman spectroscopy showed a similar irradiated structure whereas the glass evolutions were controlled by the electronic energy loss in the ion track formation regime for Kr-ion irradiation or by the nuclear energy loss for Au and OSIRIS irradiation. The similar irradiated structure despite different irradiation routes, suggests that the final structural state of this sodium borosilicate glass is mainly controlled by the glass reconstruction after the energy deposition step. (authors)