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

¹ CEA/DSM/DRECAM, Laboratoire des Solides Irradiés, UMR 7642, CNRS-CEA-École Polytechnique, École Polytechnique, 91128 Palaiseau Cedex, France
² CEA/DEN/DTCD/SECM, Laboratoire d'études du Comportement à Long Terme, CEA Valrho-Marcoule, BP 171, 30207 Bagnols-sur-Cèze Cedex, France

Corresponding author: genia@poly.polytechnique.fr

Received: 15 April 2008
Accepted: 7 October 2008
Published online: 14 January 2009

Abstract

The effect of β-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 ~ 10⁹ 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 Ce⁴⁺ 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.