Migration and segregation of sodium under beta-irradiation in nuclear glasses

Raman,B-11 Nuclear Magnetic Resonance (NMR) and X-ray Photoelectron (XPS) s pectroscopy investigations have been made on a series of beta-irradiated al uminoborosilicate glasses. This work shows the following changes of the gla ss structure under beta-irradiation: (i) an increase of glass polymerizatio n, (ii) an increase of boron in a trigonal environment and (iii) no modific ation in the aluminum environment during irradiation. These glass modificat ions under beta-irradiation can be correlated with the migration of sodium outside of the Si and B glass network formers, Moreover, XPS experiments sh ow a strong decrease of the sodium concentration at the surface of these ir radiated glasses. This study presents therefore strong evidences of migrati on and segregation processes of sodium during a beta-irradiation in thr bul k for these simplified aluminoborosilicate glass compositions. (C) 2000 Els evier Science B.V. All rights reserved.