Ion conducting phosphate glassy materials

Fast ion conducting (FIC) phosphate glasses have become very important due to a wide range of applications in solid-state devices. We present an overview on silver based fast ion conducting phosphate glasses. Silver phosphate glasses containing chlorides of some metals viz; Li, Na, Mg, Pb and Cu [Ag2O–P2O5–xMCly, where x = 0, 1, 5, 10 and 15 wt% and y = 1 when M = Li or Na and y = 2 when M = Mg, Pb or Cu] have been synthesized by melt quenching technique. Studies on these glassy materials characterized by X-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetric techniques and ion transport measurements are presented. The FT-IR studies support the formation of P–O–M linkages. The values of glass transition temperature (Tg) of the glassy materials containing lithium or sodium chloride have been found to decrease with increasing dopant concentrations indicating expansion of the glassy network. On the other hand, the Tg values increase with increasing magnesium, lead or copper chloride concentrations in silver phosphate glasses. This indicates an increase in cross–link density and enhanced chemical durability of these glassy materials. Ion transport studies suggest that the values of electrical conductivities of the metal chloride doped glassy materials are higher than those of the undoped ones and, at a particular dopant concentration, the following trend is observed.σ (–LiCl) ≥ σ (–NaCl) > σ (–MgCl2) > σ (–PbCl2) > σ (–CuCl2)These results are supported by the experimental results of FT-IR spectral and thermal studies.