Synthesis, electrical conduction and structure–property correlation in (50 − x) Ag2O–50P2O5–xCoCl2 glassy systems

Silver–cobalt–phosphate glasses of (50 − x) Ag2O–50P2O5–xCoCl2 composition with x varying between 0 and 15 mol% were prepared by a melt quenching technique. These glasses were characterized by X-ray diffraction, Fourier transform infrared spectroscopy and differential scanning calorimetric techniques. Their thermal (Tg, and Tc) and electrical properties (ionic transference number and electrical conductivity) have been investigated. Infrared spectral studies indicate the formation of P–O–Co bonds in these glasses that replace PO−…Ag+ bonds. The results of thermal studies are in accordance with the FT–IR findings and support the formation of P–O–Co bonds. The Tg and Tc values were found to increase with increasing amount of CoCl2 indicating increased cross-link density and enhanced chemical durability of the synthesized glasses. Transference number measurements show that these glasses are essentially ionic conductors. The electrical conductivity (σ) of silver–phosphate glasses doped with 5 mol% CoCl2 is found to be the maximum. The σ values obtained for different compositions of the dopant CoCl2 have been correlated with the structural changes in the silver–phosphate glass matrix.