IONIC-CONDUCTION IN OXYSULFIDE GLASSES FOR THE LI2S-B2O3 (-LIBR) SYSTEMS

Oxysulfide glasses in systems Li2S-B2O3(-LiBr) have been prepared and studied by differential scanning calorimetry and electrical measuremen t. In particular, the effects of Li2S as a modifier and LiBr as a dopa nt on glass transition temperature and conductivity of the glasses are studied. The results demonstrate that for the glasses of Li2S-B2O3 sy stem when the Li2S content increases, both the glass transition temper ature and activation energy of conduction increase, and reach a maximu m in the range 30-33 mol% Li2S. The addition of LiBr decreases the gla ss transition temperature, but enhances pronouncedly the ionic conduct ivity of glasses. These results are discussed in reference to variatio n of the structural entities with the fraction of 4-coordinated borons in the glass.