Structure-property relationships of Fe₂O₃ doped novel oxyfluorophosphate glasses

The relationship between the network structure and properties of iron containing novel oxyfluorophosphate glasses with the composition 20ZnO-20CaF₂-(60 - x)P₂O₅:xFe₂O ₃ with 0 ≤x ≤5 mol% has been studied. The density, molar volume, oxygen molar volume and oxygen packing density studies helped to understand the structural changes occurring in these glasses. The dissolution rate and pH of the immersion liquid are measured to explain the chemical durability of the glasses. Differential thermal analysis studies are carried out to analyze the thermal stability of the studied glasses. Deconvoluted infrared and Raman spectra of the glasses are analyzed to determine the relative areas of the vibrational bands corresponding to different structural units. Analysis of the vibrational spectra in conjunction with the other properties reveals that Fe₂O₃ enters the glass matrix in the form of Fe ^{2 +} and Fe^{3 +} ions through the formation of more stable POFe^{2 +} and POFe^{3 +} bonds at the expense of easily hydrated POP bonds.