Influence of external b-irradiation in oxide glasses N. Ollier a, * , B. Champagnon a , B. Boizot b ,Y.Guyot a , G. Panczer a , B. Padlyak c a LPCML, B^ atiment Lippmann, 12 rue Amp  ere, Domaine Scientifique de la DOUA, 43 Bd du 11 novembre, 69622 Villeurbanne cedex, France b Laboratoire des Solides Irradi es, UMR 7642 CEA-CNRS-Ecole Polytechnique, Ecole Polytechnique, 91128 Palaiseau cedex, France c Department of Physics, Academy of Bydgoszcz, Weyssenhoff Square 11, 85-072 Bydgoszcz, Poland Abstract Radiation effects in oxide glass as external b-irradiation has been investigated by Raman spectroscopy, Cr 3þ lu- minescence and EPR spectroscopy to analyze microstructure evolution. Comparison between simplified and complex glasses (high-level nuclear waste glass analogue) was undertaken. Migration and segregation of sodium have been confirmed on simplified irradiated glasses by a polymerization increase and dissolved oxygen presence. Densification underirradiationhasalsobeendemonstratedwiththeincreaseofthree-memberedsilicateringsinsilicateglassandthe decrease of the average Si–O–Si angle in the borosilicate glass. In both glasses, Cr 3þ crystal field was increased, sug- gesting a Cr–O length decrease. The complex borosilicate glass responds differently: densification effect and Na seg- regationwerenotdetected.Under b-irradiation,electron-trappingprocessesonCr 6þ occurred,formingCr 4þ andCr 5þ species. Ó 2003 Elsevier B.V. All rights reserved. 1. Introduction Radiations from beta and alpha decay can produce structural changes in glasses. In particu- lar,somechangesoccurinhigh-levelwasteglasses submitted to radiation [1,2]. Therefore, under- standing the glass structure change under irradia- tion is important to predicting the long-term behaviourofthismaterial.Evenifradiationeffects on SiO 2 structure have been extensively studied [3,4] and external beta irradiation on six oxides glasses have been recently studied by Boizot et al. [5,6], to our knowledge, mechanisms in complex glasses are limited. To simulate the b dose irradi- ation accumulated during nuclear waste storage, external electron irradiation has been performed with a Van de Graaff accelerator. This paper aims to compare the changes in a complex borosilicate glass having a composi- tion very close to the French nuclear SON68 bo- rosilicateglasswiththoseofsimplifiedborosilicate and silicate glasses. Raman, Cr 3þ photolumines- cence and EPR spectra were investigated. Raman * Corresponding author. Tel.: +33-1 69 33 45 18; fax: +33-1 69333022. E-mail address: ollier@hp1sesi.polytechnique.fr (N. Ollier). 0022-3093/03/$ - see front matter Ó 2003 Elsevier B.V. All rights reserved. doi:10.1016/S0022-3093(03)00307-7 Journal of Non-Crystalline Solids 323 (2003) 200–206 www.elsevier.com/locate/jnoncrysol