The ionic conductivity and structure of Li(2)O-ZrO(2)-SiO(2) glasses

Abstract

The ionic conductivity of Li(2)O-ZrO(2)-SiO(2) glasses has been designed and analysed on the basis of a mixture design experiment with constraints. Models for predicting ionic conductivity and activation energy of these glasses from composition have been induced, and the regression models fitted to data were statistically significant. The optimal composition for the best ionic conduction based on these fitted model was 55Li(2)O.10ZrO(2).35SiO(2) and its ionic conductivity at 300 K and activation energy were 1.07x10(-5) S/cm and 46.98 kJ/mol, respectively. Raman and FT-IR measurements have been carried out with some glasses. These spectra showed that Zr(4+) ion incorporation caused the breakdown of Si-O-Si bonds. The substitution ZrO(2) for SiO(2) caused the depolymerisation into SiO(4) units with 4 NBO/Si. On the other hand the substitution of ZrO(2) for Li(2)O caused the polymerisation from monomer to dimer and/or chains of SiO(4) units.