Determination of the environment of lanthanide ions in a simplified non-active nuclear glass and its weathering gel products - Europium as a structural luminescent probe

In order to explore the complex structure of the French nuclear glass (SON68) and its weathering gel products, four simplified Eu3+ doped matrices relative to the four main glass forming oxides have been studied by fluorescence line narrowing. The precise calculation of their crystal field parameters and the correlation with those of the nuclear glass and its weathering gels allowed us the determination of the nature of the trivalent europium ion environments in a simplified SON68 type glass and gels. The glass presents two sites for europium, the first one is a silicate one and the second is mixed aluminate and borate one. Both sites in the different gels are similar to the glass. The first site is mainly a silicate one with the presence of phosphate groups, and the second is an aluminate one with the possible presence of boron in the neighborhood of the rare-earth. This article led us determine the structure around lanthanide ions in the SON68 glass and its weathering gels in spite of the water leaching on glass surface (lixiviation).