Barium oxide–doped silver phosphate glass

Silver phosphate glasses doped with 0, 5, 10, 15 and 20 wt% BaO were synthesized and characterized. X-ray diffraction studies revealed that the glasses are amorphous in nature. Infrared spectral studies have shown the presence of characteristic P–O–P linkages of linear phosphate chains, presence of O–P–O units in the phosphate tetrahedral and the formation of P–O–Ba bonds in the doped glass. It is also confirmed that, due to doping of BaO, loosening of glassy structure occurred and the glass became more disordered. Differential scanning calorimetric studies revealed that glass transition temperature increased with BaO concentration. Scanning electron microscopy studies showed that BaO doping modifies the microstructures of the glass. Electrical conductivity measurements, between 303 to 373 K, in the frequency range from 0·1 kHz to 10 kHz, have indicated that all glasses are ionic conductors with Ag⁺ ions as the charge carrier. The electrical conductivities of the doped silver phosphate glass were found to be higher than that of the undoped silver phosphate glass. Results have shown that dielectric constants increased with increase in temperature at all frequencies and decreased with increase of frequency. Decrease in dielectric constants for Ag₂O-P₂O₅ and 20 wt% doped BaO at 373 K are 77 and 85%, respectively, when frequency increased from 0·1 to 0 10 kHz. Dielectric losses in all the glasses decreased with frequency at a particular temperature. It was also found that BaO-doped glass has about 60% more antibacterial property.