The structural changes induced by the addition MoO3 and Fe2O3 in lead-phosphate glasses

The relationship between the composition and structure of x(MoO3 center dot Fe2O3)(1-x)[2P(2)O(5)center dot PbO] with 0 <= x <= 50 mol% glass system has been investigated by FT-IR and Raman spectroscopy. With the increasing of modifier oxide content, the shapes of the IR and Raman bands change due to the replacement of the P-O-P bonds for the most moisture resistant Fe-O-P bonds and also, due to the appearance of the Mo-O-Mo asymmetric stretching vibrations in [MoO4] tetrahedron. The very strong depolymerization which appears in these glasses is observed by decreasing in intensity of the specific bands of phosphate network and by increasing of the characteristic bands of the very short chain phosphate units Q(0) and Q(1).