EPR study of transient metal ions and radiation defects in the materials for radioactive waste immobilization
From the analysis of electron paramagnetic resonance (EPR) data, the speciation of transition metal ions and the structure of anionic motif of glassy materials suitable for a long-term storage of solid radioactive waste were studied. The responses due to Mn2+, Fe3+ and Cu2+ ions were found in EPR spectra of both unirradiated and -irradiated glassy materials. No lines with hyperfine structure due to 51V(IV) were observed in the spectra of V2O5-doped glassy materials. The possible reason is stabilization of either V(III) or V(V) oxidation state. Anionic motif of the structure of the silicate-based glassy materials is built mainly of silicon-oxygen tetrahedra with two-three bridging oxygen ions.