ИСТИНА

While Tc speciation in borosilicate glasses is well-known [1,2], no data on Tc in alumino(iron) phosphate glasses have been found. Re is the best surrogate for Tc including the study of nuclear waste vitrification. Four glasses with chemical compositions (mol.%) 40 Na2O, 20 Al2O3, 40 P2O5 (Re-1 and Re-2) and 40 Na2O, 10 Al2O3, 10 Fe2O3, 40 P2O5 (Re-3 and Re-4) each doped with 1 mol.% ReO2 were prepared under oxidizing (Re-1 and Re-3) and reducing (Re-2 and Re-4) conditions using a quenching method. The samples Re-1 and Re-2 were predominantly amorphous but contained minor AlPO4 phase (phosphotridymite) and aggregated (Re-1) or individual (Re-2) crystals of metallic Re. Residual Re content in glass was low. The samples Re-3 and Re-4 were fully amorphous. All the Re was found to be dissolved in glass where its concentration reached 1.6-1.8 wt.%. Infrared spectra consisted of the bands typical of stretching and bending modes in phosphorus-oxygen glass network. No effect of Re was found due to its low content in glasses. XANES Re L3 edge demonstrated predominantly Re (VII) with some admixture of Re(0) in the samples Re-1 and Re-2. No Re(IV) has been found that is consistent well with reference data on Re in borosilicate glass [3]. 1. M. Antonini et al. EXAFS and Near Edge Structure, Springer, 1983, pp. 261-264. 2. M. Antonini et al. J. Non-Cryst. Solids. 71 (1985) 219. 3. W.W. Lukens et al. Chem. Mater. 19 (2007) 559.