Correlation between valence state of tin and elastic modulus of Sn-doped Li₂O-B₂O₃-SiO₂ glasses

The correlation between the longitudinal elastic modulus c₁₁ and tin valence state in Li₂O-B₂O₃-SiO₂ ternary glasses is investigated. Substitution of B₂O₃ for SiO₂ increases the glass-transition temperature and c₁₁ but decreases the melting temperature. ¹¹⁹Sn Mössbauer spectra show that the valence state of tin increased with increasing molten temperature, T_molten, in air, and that it also affects the c₁₁ value even though the 1.0 mol. % addition. The c₁₁ values, whose error bars are governed by those of density, suggest that the addition of SnO₂ increases c₁₁ whereas SnO decreases. The relationship between T_molten and the amount of Sn²⁺ suggests that the main factor affecting the tin valence state is oxygen, whose reactivity may correlate with the glass melt viscosity.