Infrared reflection spectra of vitreous phosphates (1 − x − χ)Li2O − xCdO − χ P2O5 are analysed in relation to the conformation when it is known. The evolution of the spectra with the different constituents is studied and the oxide forming-character of CdO is discussed.

The regular melting-quenching method allowed isolating very large vitreous domains within the ternary system Li 2 O-P 2 O 5-Fe 2 O 3 at 1100˚C. The vitrification and crystallization effects are discussed in terms of phosphorus pentaoxide concentration (mol%). In the course of the present study, we analyzed chemical durability along the glass domain and many sample glasses were isolated. We noticed that our compounds demonstrated very high chemical resistance to attack, even with very highly concentrated mineral acid solutions. This behavior can be assigned to the presence of poorly crystalline phases in these glasses, which tended to increase as the Fe 2 O 3 content increased. This property is a prerequisite for many interesting industrial applications. XRD, IR spectroscopy and SEM micrographs allowed an efficient investigation of the structural changes versus composition within ternary diagrams. The results were found to be consistent with the regular structural changes of phosphate glasses.

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Vitreous and relevant crystalline polymorphs of P2O5 have been synthesised and characterised by X-ray diffraction and Raman scattering spectroscopy. On the basis of the crystallographic data of single crystals of the three varieties H-P2O5, O-P2O5 and O'-P2O5, the interpretation of vitreous P2O5 Raman spectrum was given taking into consideration the short and intermediate range order. It inferred that the intermediate range order in v-P2O5 can mainly be described in terms of a mixture of both high temperature modifications, with however predominance of O'-P2O5. This hypothesis has been substantiated by in situ Raman study of v-P2O5 recrystallisation.

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