STRUCTURAL RELATIONSHIP BETWEEN VITREOUS P₂O₅ AND ITS RELEVANT CRYSTALLINE POLYMORPHS BY RAMAN SPECTROSCOPY

Abstract

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-₂O₅ 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.