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The structural study of lanthanum sodium aluminoborosilicate (55SiO 2 -(25-x) Al 2 O 3 -xB 2 O 3 –15Na 2 O–5La 2 O 3) glasses were investigated. The structural characterization by solid state Nuclear Magnetic Resonance have outlined the role of aluminum/boron substitution. This study has a particular interest for applications like the nuclear waste glass storage. Various types of matrices have been considered for containment: borosilicate, aluminosilicate and aluminoborosilicate, the latter with a high rare earth content ability is of particular interest. This system will be considered in our study from the point of view of a simple five-oxide glass, rich in TR 2 O 3 (TR = La), in order to provide additional elements of understanding to the model glasses of containment for nuclear waste, lanthanum simulating, among other things, all lanthanides as well as minor actinides contained in the waste. In this paper, ourwork focused on the study of the influence of boron on the structure by solid state Nuclear Magnetic Resonance (NMR). In particular, we examine the impact of aluminum/boron substitution in a series of glasses in term of structural changes. • We have investigated a composition of glasses with a high content of rare earth elements. • 29Si,27Al, 23Na and 11B MAS NMR was used to describe the vitreous aluminoborosilicate network. • Glasses homogeneity is discussed according to the influence of boron/aluminum substitution. • NMR spectroscopy gave a better discerption to discuss the structure in term of Qn(mAl) and Qn species. [ABSTRACT FROM AUTHOR]

Abstract: From a presentation of the various nuclear magnetic resonance (NMR) experiments that allows to characterize the local structure and dynamics of oxide glasses and melts, we show that it becomes possible to evidence not only the details of the coordination state of the constituting atoms but also the nature of polyatomic molecular motifs extending over several chemical bonds. [Copyright &y& Elsevier]