STRUCTURAL STUDY OF IRON PHOSPHATE-GLASSES

The effect of iron content on the structure of xFe(2)O(3)(100-x) P2O5, (15 less than or equal to x less than or equal to 50), glasses was in vestigated by Raman spectroscopy and x-ray diffraction. The Raman spec tra for these glasses indicate that the nature of the phosphate networ k changes from the chain like metaphosphate to the orthophosphate stru cture with increasing Fe2O3 content. As the Fe2O3 content increased fr om 15 to 38 wt% the average length of the polyphosphate chains became shorter as the iron ions were effective bonding the ends of the chains to the surrounding glass structure. At higher Fe2O3 content, up to 50 wt% the iron ions occupy tetrahedral sites as a result of iron substi tution into phosphate chains and formation of FeO4 tetrahedra. The str ucture of the glass differs from that of the crystal but the local env ironment of the iron ions is retained in the glass and crystallised co unterpart of these iron phosphate compositions.