Powellite-Rich Glass-Ceramics: A Spectroscopic Study by EPR and Raman Spectroscopy

International audienceThe aim of this study is to better understand the incorporation of rare earth elements in glass-ceramics of nuclear interest. We synthesized glass-ceramics from glasses in the system SiO 2-B 2 O 3-Na 2 O-CaO-Al 2 O 3-MoO 3-Gd 2 O 3 by various heat treatments. Gadolinium is used both as a spectroscopic probe and as a minor actinide surrogate. Glass-ceramics contain only one crystalline phase in the bulk: powellite (CaMoO 4). This phase can incorporate Gd 3+ and Na + ions by substitutions on the Ca site. We demonstrated that the charge compensation by Na + favors the rare earth elements incorporation. Moreover, the incorporated elements do not seem to be randomly distributed into the powellite structure