Antimony and silicon environments in antimony silicate glasses

摘要

Antimony silicate glasses, of general formula xSb_2O _3·(1-x)SiO_2 (0.1≤x≤0.78), have been prepared by melt-quenching and their structures studied using ~(29)Si MAS NMR spectroscopy, ~(121)Sb Mssbauer spectroscopy and Raman spectroscopy. Oxidation during melting gives rise to Sb~5 in concentrations, which increase linearly with x to give a value of ～10% when x=0.78. ~(121)Sb Mssbauer spectra show Mssbauer shifts and quadrupole splittings consistent with Sb~3 in a [:SbO_3] trigonal pyramid, similar to that in crystalline Sb_2O_3. A broad band in the Raman spectrum at ～410 cm~(-1) is due to the vibrations of such a unit. The dependence of the silicon Q~n speciation on x can be interpreted by the formation of SbOSb links possibly to form rings of 4 [:SbO_3] units such as are found in valentinite.