Antimony Silicate Glasses

M Mee(1), B C Davies(1), R G Orman(1), M F Thomas(2), D Holland(1)*

(1)Department of Physics, University of Warwick
(2)Department of Physics, University of Liverpool

Antimony silicate glasses, of general formula xSb2O3•(1-x)SiO2 (0.1 < x < 0.78), have been prepared by melt-quenching and their structures studied using 29Si MAS NMR spectroscopy, 121Sb Mössbauer spectroscopy and Raman spectroscopy. Oxidation during melting gives rise to Sb5+ in concentrations which increase linearly with x to give a value of ~ 10 % when x = 0.78. 121Sb Mössbauer spectra show Mössbauer shifts and quadrupole splittings consistent with Sb3+ in a [:SbO3] trigonal pyramid, similar to that in crystalline Sb2O3. A broad band in the Raman spectrum at approximately 410 cm-1 is due to the vibrations of such a unit. The dependence of the silicon Qn speciation on xthe mole fraction of Sb2O3 can be interpreted by the formation of Sb-O-Sb links possibly to form rings of 4 [:SbO3] units such as are found in valentinite.