Powellite‐Rich Glass‐Ceramics: A Spectroscopic Study by <scp>EPR</scp> and Raman Spectroscopy

Abstract

The aim of this study was 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 incorporation of rare‐earth elements. Moreover, the incorporated elements do not seem to be randomly distributed into the powellite structure.