Irradiation effects in oxide glasses doped with transition and rare-earth elements

Abstract

International audienceThe effect of -irradiation on silicate and aluminoborosilicate glasses doped with transition metals (TM) and rare earth (RE) elements has been studied using Electron Paramagnetic Resonance (EPR), Raman and luminescence spectroscopy. Irradiation leads to the reduction of both Cr and Mn ions in both types of glass matrix. It is shown that even small amounts of TM dopants completely block defect production, as occurs under irradiation in non-doped glasses. As well, TM doping results in the disappearance of structural changes in the glass (densification, polymerization increase and Na migration) for doses of ~ 10 Gy. Unlike TM-doped matrices, incorporation of RE ions into aluminoborosilicate glass blocks neither defect production nor structural changes in glass matrices during irradiation. Simultaneously, we observe a reduction of RE ions, most clearly demonstrated for Ce ions in aluminoborosilicate glasses. We propose that the relative stability of the different charge states of the RE ions is linked to the efficiency of the reduction process, and therefore to the evolution of the glass structure during irradiation

Optical properties and valence state of Sm ions in aluminoborosilicate glass under β-irradiation

“…5). This behavior has also been observed previously for other rare-earth dopant in glass like gadolinium (after b-irradiation) [24] and samarium (after c-irradiation) [18]. We have only considered EPR defect lines in this work because the g values of Sm 3+ ions (g k $ 0.11, g ?…”

“…Recently we studied optical properties and the reduction processes of Sm 3+ ions into Sm 2+ by c-irradiation in aluminoborosilicate glasses [18]. We found also that reversible conversion of Sm charge state takes place under b-irradiation [21].…”

“…For the glass synthesis we used the same protocol as in [18,21]. The nominal compositions of the glasses are given in Table 1.…”

“…The reduction mechanism of Sm 3+ ions into Sm 2+ has been observed in aluminosilicate [11][12][13][14][15][16][17][18][19][20], aluminoborate and sodium aluminoborate glasses [13,14]. Two ways are generally applied in the literature in order to produce the Sm 2+ charge state in amorphous materials, namely heating in the presence of reducing gases [15,16] or different irradiations like X-ray [17] c- [14,18] and laser pulses [11,13].…”

“…Two ways are generally applied in the literature in order to produce the Sm 2+ charge state in amorphous materials, namely heating in the presence of reducing gases [15,16] or different irradiations like X-ray [17] c- [14,18] and laser pulses [11,13]. In the glass heated in reducing atmosphere H 2 , molecules deplete the oxygen ions surrounding Sm 3+ , resulting in the formation of Sm 2+ ions:…”