J. Phys. IV France 02 (1992) C2-165-C2-170
Influence of the fluorine-oxygen substitution on the ionic conductivity properties of lithium tellurite glassesJ. M. REAU1, B. TANGUY1, J. PORTIER1, J. M. ROJO2, J. SANZ2 and M. P. HERRERO2
1 Laboratoire de Chimie du Solide du CNRS, Université de Bordeaux I, 351 Cours de la Libération, 33405 Talence Cedex, France
2 Instituto de Ciencia de Materiales, CSIC, Madrid, Spain
A large range of glassy compositions has been found inside the ternary LiF-Li2O-TeO2 system. The influence of the fluorine-oxygen substitution on the ionic conduction properties of (50-x)LiO0.5-(x)LiF-(50)TeO2 ([MATH]) glasses has been investigated. These results have been correlated with the data relative to ion distribution and microstructure obtained by NMR and TEM. A maximum of conductivity associated with a minimum of activation energy is observed for [MATH]. The composition dependence of conductivity with rising x can be explained by a progressive decrease of the F-F associations around the Te4+ ions and a simultaneous increase of the Li-F associations. The clustering of the Li+ and F- ions produces small domains which hinder the Li+ ions diffusion in these glasses.
© EDP Sciences 1992