Phase Separation in Li-Si-O-N Oxynitride Glasses

Phase separation in Li-Si-O-N oxynitride glasses has been studied in terms of the effect of nitrogen on the miscibility. Substitution of nitrogen for a part of oxygen lowers the miscibility temperature linearly with an increase in the nitrogen content. An oxynitride glass with ca. 10eq% nitrogen shows a lower miscibility temperature by about 90K than that of the corresponding oxide glass without nitrogen. The decrease in the electrostatic attractive force between lithium and the network anions caused by the covalency of nitrogen may be responsible for an increase in the miscibility.