High temperature brillouin scattering study of lanthanum and sodium aluminoborosilicate glasses

This work is devoted to the study of a rare earth aluminoborosilicate glass, whose molar composition is 55SiO2-(25-x)Al2O3-xB2O3-15Na2O-5La2O3, which is considered as a model glass for nuclear waste immobilization, by simulating all lanthanides as well as minor actinides contained in nuclear waste with lanthanum. From a structural characterization point of view, these glasses have been studied by Brillouin scattering. The temperature dependence was studied over a wide temperature range from room temperature to 1400 K in order to highlight the important role of the effect of aluminum/boron substitution. The influence of annealing was clearly observed in frequency and width. The temperature dependence of the Brillouin frequency shift was used to determine the glass transition temperature and the relaxation temperature.