Investigations on oxyhalide glasses synthesized by microwave assisted process

Glass formation and properties in the system xPbCl₂-15PbO-(85-x) PbBr₂ (where 0 ≤ x ≤ 25) has been prepared by microwave method. The glass forming tendency of the admixtures was also been studied by determining the Hurby’s factor (H_R). H_R values of the investigated glasses lie in a short range of 0.14 to 0.24; hence preparation of these glasses is very difficult and requires suitable experimental conditions. Lead bromide and lead chloride are inter-substituted by keeping the concentration of PbO at 15 mol%. Properties like glass transition temperature (T_g), jump in heat capacity (ΔC_p) at T_g, width of glass transition (ΔT), show a composition dependent trend. The stability indices such as H′ and S have also been calculated. These values reveal that PbCl₂ rich glasses are less stable while PbBr₂ rich glasses are stable, which is well supported by chemical durability studies. The calculated values of glass formation indices fall in right range (G≥20 for glass formers, for conditional glass formers 10≤G≤20 and G<10 for glass modifiers) for compositions studied in the present work.