Relaxation study of pre-densified silica glasses under 2.5 MeV electron irradiation

Nadège Ollier (1) , Matthieu Lancry (2) , Christine Martinet (3) , Valérie Martinez (4) , Sylvie Le Floch (5) , Daniel R. Neuville (6)

1 LSI - Laboratoire des Solides Irradiés - Irradiated Solids Laboratory
2 ICMMO - Institut de Chimie Moléculaire et des Matériaux d'Orsay
3 ILM - Institut Lumière Matière [Villeurbanne]
4 iLM - SOPRANO - iLM - Spectroscopies optiques des matériaux verres, amorphes et à nanoparticules
5 ENERGIE - (nano)Matériaux pour l'énergie
6 IPGP (UMR_7154) - Institut de Physique du Globe de Paris

We examined the “relaxation properties” of pre-densified synthetic fused silica glass under 2.5 MeV electron irradiation. The densification of the glass was either obtained by hot compression (5 GPa-350 °C and 5 GPa-1000 °C) or via a thermal treatment increasing its fictive temperature (T_f = 1050, 1250 and 1400 °C). Under irradiation, the pre-densified silica glasses exhibit a relaxation of their macroscopic density with increasing integrated dose. Density was reduced for hot compressed silica and increased for T_f samples with different relaxation rates but it is remarkable that all sample densities follow a trend towards the same equilibrium value around 2.26 for a dose larger than 10 GGy despite a different final topology. After irradiation of hot compressed silica, the Raman spectra display a significant increment of 4 and almost 3-membered rings whereas they exhibit a glass density reduction; demonstrating that a D₂ band increase cannot be considered as an absolute marker of the glass compaction. The correlation between density and D₂ intensity remains valid until silica density remains lower than 2.26. In contrast, the FWHM of the main band peaking at 440 cm^-1 appears to remain correlated to the silica glass density for all investigated samples.

Domaines: Chimie; Physique [physics]; Sciences de l'ingénieur [physics]

Nadège Ollier, Matthieu Lancry, Christine Martinet, Valérie Martinez, Sylvie Le Floch, et al.. Relaxation study of pre-densified silica glasses under 2.5 MeV electron irradiation. Scientific Reports, 2019, 9, pp.1227. ⟨10.1038/s41598-018-37751-9⟩. ⟨hal-02285878⟩